Red Battery symbol, then abs dsc please help
 

Well I started driving 2001 x5 3.0i 5mt.
Stopped to take some pictures of the car, when I got back in and started the car I was hit with red battery symbol.
I restarted car, same thing so I continued to drive.
When pulling up to my destination I was hit with abs and dsc and all.
When starting car to leave back home I got around the corner with battery lights, abs, dsc, and no the airbag lights!
Pulled over to restart car, now car doesn't start. Leaving my car in the city for acouple days so please someone help me try to figure out before I go to the shop and waist money.

Battery seems to be fully charged. When turning key over all I get is two click clicks all lights on dash illuminate but no start.

Before i pulled over windows were rolling up so slow.
Then with car off the windows went up fast like normal.

Could it be alternator???
Sorry for long post but information should help.

Thanks

Normal BMW Christmas Tree dashboard when the charging Voltage is low and/or the battery is bad.

This could be due to a bad alternator. but I had a battery with a bad cell and it caused the exact same problem as you described, turned out the alternator was fine, 50k miles later and still on the same alternator but a replacement battery.

Ya that's what I was thinking. I'dk I hooked a battery charger to jump it but it says battery is fully charged and just won't turn over.

So many battery chargers are capable of some form of battery testing or estimating a batteries charge. But many are misleading as well.

A bad battery can have a good surface Voltage but not enough output.

With any electrical system problem, you start by verifying the battery is good. A poor mans check it to put a Voltmeter on the battery terminals or the under hood jumper terminals and measure the battery Voltage at rest, then turn the headlights on for 2 minutes and see how low the Voltage drops.

If you do not have a Voltmeter you can use the Hidden OBC Menu and display the Voltage directly on the dashboard.

BMW X5 - Access the Hidden Onboard Computer (OBC) Functions.

Also what happens if you attempt to jump start the vehicle?

I also keep something like this in my car as well - http://www.amazon.com/CP-02B-8000mAh...ni+jumper+pack

charging issue .

Get your credit card out-buying either a battery, alternator or both. But, simple solutions if that helps.

When I try to jump start I get same thing.
Christmas lights on dash CLICK CLICK and no turn over.

I guess next step is checking voltage... car is over 30 miles away. I left it in the city that's only problem hahah

Easy solution fix yes.... but not really trying to throw money at an alternator or a battery if it's not the issue...
It's the holidays and my money is going towards family rather than myself.
I'll double check to make sure it's battery before buying an alternator.
I'll double check fuses...


Thanks for the help so far. I got another day before I go back to the car and test and call a tow truck. It's either going to my house or to the shop

So there could also be a bad connection somewhere in the system and/or a bad engine to body ground connection.

Could be the starter as well, but with the Christmas Tree dash board, it clearly seems like a bad battery and/or an alternator problem.

You really need a multimeter to get some "real" measurements to narrow things down. Walmart, auto parts stores, home centers. Radio Shack (if they are still around) and hardware stores should have a decent meter for under $30 that will get the job done.

A few options are to remove the battery and take it to a parts store for charging and testing. If the battery is bad, you have half the job done once the battery is out.

How old is the battery? Usually 4+ years many batteries are on borrowed time often anyway.

If the battery is original, I think the problem is obvious.

^ agree

I have a meter. Just didn't have it with me at the time.
Now I just gotta drive to the car, as it's not close to my house.


I might get a battery... as I've owned the car for a around 2 years and I don't think the previous owner had a new battery so I figure it could be close to its end date

If the battery is 14 years old, it owes you nothing at this point.

BMW batteries should have the month and date stamped on top of the positive post as I recall.

I doubt it's 14 years old.. I'll check date.

If my battery was dead wouldn't I not be able to get the doors to unlock or wouldn't the windows and lights on interior not turn on?

Because all interior lights and all are bright and come on. And I can roll windows or unlock doors.

The red battery light is really a Charging System Light, not a light to tell you the battery is dead. You know the battery is dead because it stops working. The charging system runs all electrical circuits after the engine is started, the battery is only used to start the engine. You might sit in a parking lot with the radio on and the engine off, but the design intent of a battery is to start the car.

If the charging system light is on while the engine is running, then you have alternator trouble, or connection trouble of the alternator. Since alternators wear out and connection troubles are seldom spontaneous, my money is on the alternator. Specifically, the brushes that are part of the voltage regulator that can be removed from the back of the alternator. If you know how to take the regulator out, there's a small chance that you can do so without removing the alternator from the car, but I think you will need to take the alternator out to fix this.

In a related note,
My X5 was parked on the street the other day and the alarm sounded for no apparent reason. It stopped after 45-ish seconds, and went to a delayed beep every 10-ish seconds. Oddly, the battery was dead. Sorta. I got the jumper cables out and got the car going, and then put my charger on overnight.

My issue now is that I have the 4x4 symbol lit up. I was going to use my PASoft to clear the fault, but I don't have an XP machine anymore. (I have a machine that runs XP, but the power supply is toast or the main board is toast -- either way it does not turn on without more testing.) My question is, is the light on for no other reason than the battery died?

Interior lights and door locks don't draw much electricity. Turn one the bright lights, fan, radio, leave the door open and try to start the engine. If battery is dead the lights should dim. If you unlock the cluster as mentioned you can read the current amount of voltage in the battery. The best thing to do is have the battery load tested--local auto parts store will do it free. When you jump a vehicle that has a dead battery the cables should be connected for a few minutes before trying to start the vehicle. If battery is good it could be that the battery terminals just need to be cleaned. That's the easy stuff to do.

Update
 

I went to check on the x5..

When turning the heat and headlights it does dim and almost die. But if my alternator is bad and I can't turn the car on wouldn't that kill the battery alone...

Anyways I'm towing to my house instead of shop.

I will buy alternator and I will do it myself, then take the old one to be tested. Or the other way around....

And I may end up buying a battery after that.
That way I don't need to be worried about either.

Will update tomarow after I tow it home.

After the engine starts, the alternator takes over powering the electrical systems. If the alternator fails, then the battery does the work for as long as it can. So, just because the light comes on does not mean the car will die right away. My F150 took about 30 minutes to give up the ghost.

I would try a battery first IMHO. when I first purchased my x5 I noticed battery issues when the temp would drop to -25c and when I try to start the x just click ,click, .I checked the date on the battery which was a bmw battery and at the time it was less than 3 yrs old. replaced battery the following summer and it has been fine ever since. it would start in -45c weather no problem.

This is a normal symptom of a dead battery, the OP has a charging system light that's on. His battery will start the car today, but soon it will be dead too. The charging light means the alternator is on the fritz.

The cheapest thing to do is to use a set of jumper cables to start the car, then the charging system (alternator) should be able to charge the battery IF the battery is able to accept a charge. If the charging system light is on, then the battery is not the problem, the alternator is.

This is in case you need an alt Dab

Hard to argue with a lifetime warranty
https://www.fcpeuro.com/products/bmw...tor-x5-al9413x

All the alternator does is charge the battery. It doesn't power the electrical system.

Um, not correct, the alternator is responsible for powering everything in the vehicle and it also can charge the battery. That being said, depending on how the vehicle is used, often the battery does not get properly charged.

But BMW's and most modern vehicles can go haywire when the cranking Voltage drops too low and the many modules fail to properly communicate. Very strange things happen with low batteries and unstable charging systems in modern vehicles.

The alternator replenishes battery voltage at a rate exceeding draw on the battery keeping the battery at a little over 12v. The alternator does not provide power directly to anything. All systems draw the power needed to run them from the battery.

You are absolutely wrong about this and I have no idea where you learned anything about automotive charging systems. Automotive charging systems in basic theory have not changed significantly for over 100 years. In the past 20 years there have been some variations to how the systems work, but the primary purpose of the battery is to start the engine as well as stabilize and filter the charging system, which powers the vehicle electrically components. Why do you think that majority of alternators today are typically between 120 and 200 Amp? When was the last time you say a battery charged at 120+ Amps?

There are a few vehicles that are designed to draw from the battery as a fuel saving measure, but this is only under very controlled situations. My GMC truck does occasionally draw directly from the battery and some of the Mazda Skyactive systems do some similar things. But again, these are very specific situations and the alternator does kick back in to handle the bulk of the electrical load on the vehicle.

Let me ask this basic question, IF a fully charged Lead/Acid battery has a terminal Voltage of 12.6 Volts, why do you find the majority of the vehicles operating at 13.5-14.5 Volts? Where do you think this additional power is coming from?

Maybe you are confusing where power connections are made, this is a very different story and a power connection is not necessarily the source of the energy.

I just do not understand how people can think this is accurate information.

So did you have any formal Automotive Training?
Did you ever make a living repairing vehicles?
Were you ever a Certified Mechanic?

If the answer was yes to any of the above, you must have not been aware of anything you did on a daily basis.

While your symptoms sound like an alternator issue I would not buy anything yet.

When you get it home remove the battery cables and clean the posts and the connector. Then charge the battery. If after the battery has been charged your X won't start then have the battery load tested to verify if it is good or bad.

Once the battery is charged or a new one installed unlock the cluster. Read the battery voltage using the cluster. Start it up and read the alternator output.

The reason I am suggesting this process is there are other possible causes for your problem that are unconnected to the battery or the alternator. Best practice is to spend the time to troubleshoot to find the root cause before buying parts.

The the failure of an alternator does not mean the battery is also bad. The failure of a battery does not mean the alternator is going to fail. The life cycles are different.

Before we start off the day's postings slagging everyone's automotive knowledge and the source of energy, I would suggest a few simple tests with a volt ohm meter.

AFTER CHARGING THE BATTERY
With the test meter connected to the battery posts, read the voltage_____
With Key in the engine on position, and meter connected to the battery the reading is _________
With meter still connected to the battery, crank the car. What is the LOWEST reading that comes on?___________
Engine running, what is the voltage at the battery?_______

Report back and and we can have a good understanding of the Starting system. This is the FIRST test in checking a starting/charging system. We will stay will volts as I am sure you do not have a carbon pile load tester in your garage that can load 50% of cold cranking amps RATING to the battery after charging 30 mins at 60 amps, or 2 hrs at 10 amps. This test shows battery condition and ability to hold and store energy. Most of the "parts store" employee hand held testers only load 100 amps and call it quits.

By the way, that above test was being done way back in the 40's, 50's, 60's by Sun Electric as the standard baseline for starting systems.

Now with TESTING, not guessing we will determine what is going on and be able to assist the OP.

Now back to flaming :hammer::hammer::fencing::explode:

The battery and the alternator Both provide power to the car electrical system. You can not start an engine on the alternator, but you can run an engine on the alternator.

https://www.youtube.com/watch?v=RGtw2A4SI1U

Here's an analogy as to how the alternator and battery work. If you filled a bathtub with water and kept the water from the sprout running, but open the drain. Are you bathing using the water from the tub or the sprout?

Alternators are not designed to charge up a dead battery. Using the alternator to charge a dead battery will shorten the life of an alternator.

https://www.optimabatteries.com/en-u...ead-batteries/

The vehicle electrical system is not operating at 13.5-14.5 volts that is the charge rate of the alternator. Why do they call it a 12 volts system if the actual voltage was 13.5 to 14.5?

If the charge rate of an alternator was 12 volt and the battery is 12 volt, the current would not flow from the alternator to the battery because they will be in equilibrium. An alternator charge rate has to be greater than 12 volts in order for the current to flow from the alternator to the battery.

If a battery was fully charged, the alternator regulator will prevent the alternator from overcharging the battery by not supplying a voltage to the field coil.

http://www.autoshop101.com/forms/alt_bwoh.pdf

ItThe majority of 12 Volt automotive systems operate at 13.5-14.5 Volts in case you have never bothered to check. Rarely will any modern vehicle with a properly operating electrical system ever drop to or below 12.6 Volts. As I mentioned there are a few exceptions and this has nothing to do with a battery charging Voltage it has to do with load shedding, engine power management and fuel economy. The E53 does not function this way.

13.5-14.5 Volts IS the typical operating Voltage for the majority of "12 Volt" vehicle electrical systems. This Voltage is required to keep both the battery charged and power all the accessories and loads in the vehicle.

It is called a 12 Volt system as "Nominal" 12 Volts. The typical automotive battery has a combined cell Voltage of 12.6 Volts based on thetypicaly battery chemistry. So why is is not called a 12.6 Volt system?? Simplicity sake would be a good reason. 24 Volt systems typically operate at 27-29 Volts but they are also referred to as a 24 Volt system. Again, simplicity sake would be a good reason.

Yes, in order to provide a charge to any battery, the charging Voltage needs to be greater than the battery baseline Volt. This is simple and basic electricity theory.

I just do not understand why there are just a few people here that THINK they know what they are talking about and often provide wrong or misleading information?? I realize this is a forum and often forums are for exchanging information, idea and to learn things, but I have found some of the E53 group a rather unusual bunch that really needs to open their minds a bit.

Also trying to prove a point with YouTube videos or other sources does not make you an expert, especially if you have never spend a day or years in the field. I have found many YouTube or self produced videos and documents often are full of mistakes, inaccuracies or just down right wrong information. You still need to think for yourself in the information age, because last time I checked, everything on the Internet is not 100% accurate.

We have had the Johnny Neutron that try to debunk everything someone states when they have never verified any of what is being discussed.

It seems there are a few "buddies" here that are equally as confused and/or have little to no field experience and tend to believe EVERYTHING that is put in writing or on a video. Even the manufacturers, suppliers and service manual providers make errors, omissions and just wrong statements or have incorrect procedures documented. I run into this ALL the time in the Automotive and other fields that I am involved in.

Yes, the OP needs to do some basics, test and charge the battery, verify connections, verify the charging system, check for Voltage drop. Often I make the mistake that someone has my basic knowledge and skill set and do not always start with the assumption that someone can barely open their hood, but many people are at this level. But for people to make a blanket statement that the vehicle runs off the battery is just wrong for anything other than a Tesla or golf cart, I just have no idea how anyone can even think this is they way a vehicle electrical system works.

Never claimed to be an expert in the automotive field. The only person that is making that claim on this forum is YOU.

The Youtube video was just to show that you can operate a car without a battery.

My statement was that the car runs off both the battery and alternator, not just one or the other.

The radio in my X and other cars operates just fine with the engine off and just running on the 12 volts Battery, so does the lights and the windshield wipers if I turn them on.

Are you by any chance related to Trader4. Or are you Trader4 but with a new log in?

Disagreeing is not flaming. As I see it you are the first to head that way.

Yes--it is easy to check the battery with a meter if you have what you need and know how to use it. And if he does that's great. If that is not the case and the route is to purchase one I suggest purchasing one that will do a load test. The tests you suggest should start with a fully charged battery that reads 12v. However that is not the only way to find the core problem without guessing and since the meter route had already been suggested I thought an another approach was a reasonable contribution, for OP and other readers.

Upallnight is correct that a car will run based on the alternator output only. I agree the primary function of the battery is to start the engine. However, the current needed to keep the vehicle running and power the electrical systems still comes through the battery not directly to the electrical systems. What electrical systems are connected directly to the output of the alternator?

:iagree:

Wouldn't it have to be all of them because the car will run with the battery completely disconnected?

:iagree:

Small update
 

Sorry to see argument on this post.

This morning I am going to get the x5 towed to my house. I tested at terminals yesterday and got a 10v read.

When I get it to my house I will charge it and take it and measure volts again.

After that go to autozone and check it.

After that remove alternator and take it to get checked..

Not buying any parts until late I do get my car at my house because it's to hard to do test in another city without my garage.

Alot of the info has helped me.
I'll get back once my car is at my house and battery has charged.

Originally Posted by jdstrickland
The red battery light is really a Charging System Light

Guys, This light will turn on if the charging system sees a "out of limits" (bounds) voltage in the charging circuit. It does not know anything other than volts. A shorted (collapsed cell walls) battery, a dead or dying alternator regulator, poor contact in the Alt brushes, a break in the charging circuit (Alt wiring, battery wiring grounds, etc) all can cause the light to turn on. The one I enjoyed in the past is the four way flasher indicator turned on but does not blink when a battery started to collapse and shorted out. Car started and ran fine. No codes.

Bredliner is correct as always, there is more than one way to test our vehicles leveraging the onboard monitoring. But be aware, that is monitored voltage not a live reading. All of these displays are processed by the CPU (DMU?) then displayed. In a vehicle that is normal it is good enough for 99% of users.

Under the heading of "So What?" I hold a Master SAE certificate. But I don't think that moves my random thoughts and postings to "Master Levels" as this is a DIY forum. I have seen many "masters" arguing about lots of fine points including my own two electrical engineering Master degree brothers who have ZERO auto experience. I have a lowly general technical engineering education background, so I don't count at home either.....

I think the bottom line here for all users is to double and triple check the starting /charging system voltage as everything is suspect on a 10+ year old system where you are not the only one who touched it first. Who knows what wire was left loose, or has gotten worn out or stressed out in the last few years? Batteries die every day some new some way older than 11 years. Check and test them before moving forward as batteries and wire connections and grounds will lead you way from the problem to the parts replacement process real quick. A quick jumper wire to provide a known good ground may display a weakness.

Thanks for the update. Good testing process. 10V is really low for a static state of a battery. the recharge will show the real battery state. Hopefully it is just brushes in the alt that are too worn to make contact. See other postings on DIY for brushes and alt reg fixes. Most seem to go down the replacement path with varied results from the part sources.

Let us know of your results

And in many parts of the automotive field I am in fact an expert. Trained, certified and made my living in the field for many years.

Um, no not related that Trader4 in any way shape or form. He was a real PITA and in case you have not noticed he deleted all of his posts a week ago or so from what I saw. He was a real PITA that offered nothing much to the forum members that were looking for help.

Vehicles are not all created equally, but there is something call Voltage drop that need to be taken into consideration AND keep in mind here, we are discussing BMW's. Our friends the Germans tend to do things a bit differntly then the rest of the world. Just because you may think you understand how a BMW is built does not mean you understand how the electrical system works.

The E53 and many other BMW's connect many of the electrical loads directly or very close to the battery, this does not mean the battery is meant to run or power the vehicle for extended periods of time, the Alternator is the PRIMARY DC power source for most modern vehicles.

BMW has the BST or ballistic battery cable that can and does go bad, but the purpose of this BST cable it to shed the vehicle load in case of an accident and reduce a fire hazard due to electrical problems.

But not all vehicles have connections directly at the battery. Many vehicle have load centers and/or larger fuse and relay centers that may or may not be located near the battery depending on the vehicle design.

So for someone to continue to state that the the vehicles loads are powered by the battery, this is flat wrong. I am not sure where this was learned or how this idea came about, but it clearly needs to be revisited.

The alternators primary purpose is not to be a battery charger. Until this concept can be understood, there will be no forward progress.

No arguments, just people that do not understand or want to understand!

10 Volts at the battery or where every you measured is BAD.

A fully charged 12 Volt battery should have a terminal Voltage of 12.6 Volts.

Just because the batter has 12.6 Volts does not mean it is a good battery.

A battery can have a surface charge that is greater than 12.6 Volts, but this can quickly be removed by turning the headlights on for 30-60 seconds, then let the battery rest.

Until a battery is properly charged and tested, you have no idea what shape it is in.

Problems as mentioned, could be with loose or corroded terminals, a bad BST cable and even a bad alternator.

Keep in mind that some of these vehicles also have bad engine to body grounds as well.

If you have a battery charger that claims the battery is 100% charged, you cannot use this 100% value to consider the battery any good. The battery needs to be tested with a load tester and/or a resistive/capacitive battery tester. I prefer both.

A poor mans load test is to monitor the battery terminal Voltage on a fully charged batter, turn the headlights on and if the battery drops below 12.2 Volts, I would likely condemn the battery, but always best to have a proper test preformed.

No loss. He really was a PITA that did not offer any help just whining about this part or that one and at BMW in general.

Thanks, we can at least agree on this point! :thumbup:

Funny how I asked this same question almost two years ago and you ALL were on the other side of the fence!!!! Terminators car stopped running while he was driving. The battery came loose. I told you guys that the car should have stayed running, yet everyone insisted "bmws" won't because there is too much "electrical stuff". I even offered to try this on my own X, but YOU, upallnight, got me so nervous to try it explaining that there are current spikes and what not that alternator can not correct so you would take a chance of damaging components. So which one is it? Will your BMW X5 run without a battery installed?

Always!!!!:thumbup:

NEVER remove a battery connection when the engine is running. You will not like the results of the surge damage when reconnecting it. Modules will fail, electrical components will go off the deep end. Can it be done and not have any issues? Yes, but why take the chance? THis "test" was a short cut way back in the 60's left over from post war vehicles with generators.

Loose power connections have shorted out more electrical components than anything else in history. (An assumption on my part. No actual data collected...:rofl:)

Regarding a vehicle that dies when the battery is disconnected: A good electrical system SHOULD have kept it running. But who knows what failed at the same time as the disconnect? The Regulator? The main module? The ground wire? Who knows? Maybe the alternator/wiring was DEAD/shorted before the disconnect.....

It was stated that the connection at the battery came loose. Once tighten all was well from what I remember.

I thought the car should have kept running too.

The battery dampens and filters the alternator output.

One thing that most modern vehicles do is the DME/ECU can and will kill spark and fuel if the input Voltage gets too high to protect the DME/ECU and other modules in the car in the case of a high Voltage swing. Usually 17-19 Volts it the trip point for most vehicle. No idea the exact value for BMW and I am not interesting in finding out on any of my cars.

You can arc weld with 120-200 Amps and as mentioned it is not a wise test to disconnect the battery on a modern vehicle for testing. Without the battery as a static load and filter, the alternator can do some funny things. Even filtering out AC ripple that can high peak to peak Voltages.

A $20 Voltmeter or using the Hidden OBC Menu to access the Voltage and display it on the dashboard is all that is needed. Charging and starting systems are really easy to trouble shoot as long as the EWS does not get in the way.

Learn how to use a Multimeter/Voltmeter and learn how to perform Voltage Drop testing and you can correct the majority of problems that creep up. I also use a spare pair of jumper cables to connect temporary grounds to identify and find problems.

:iagree::iagree::thumbup:

I agree with the all the troubleshooting steps mentioned above by other owners.

For my case, it was my orig alternator bearings. replaced mine with Genuine RFMD BMW (by valeo) 140amp alternator (retail at ~$600+ no tax, I got for only ~$400 including tax ) and kept the old one for autopsy/fun experiments.

Some will recommend buy RMFD or new OEM alternator for even less money. Keep in your orig alternator specs 120amp or 140amp or xxxx amp, air cooled versus water cooled .

Some will recommend DIY or go to an automotive alternator rebuild shop - defective replaceable parts like the bearings, VR and etc - most economical way to get you back on the road...

Just adding my .2 cents:


- Alternator isn't charging the battery (most cases -> the alternator is intermittently failing)
* Check terminal connections / ground cables
* Check voltage while car is OFF - should be approximately 12 volts
* Check voltage while car is idling - should be approximately 14 volts
* Check voltage at battery terminals while car is revved up a little (maybe 3k-4k RPMs) - should still be approximately 14 volts.
* Turn on everything Radio, AC/Heater and etc - the works :)

- Broken or lose accessory belt
* Check belt tension and position
* Check idler pulley and tensioner pulley

- Faulty ignition switch (can cause flickering or solid red battery light)

I never have any intentions to ignore input or defend something just because. I have no problem admitting when I am wrong. And, in this case, I am wrong about how the system works. I do stand by the poor man's methods of troubleshooting.

I agree that we are more knowledgable about some aspects of a vehicle than others and certainly there are differences in how things work from one brand to another so it is never a good idea to universally apply how things work. In my case I was thinking only of an E53 because that is forum.

JFOJ, Regardless of certification, experience or day job, I think when one declares themselves an expert they begin to be less effective. I suggest you use your knowledge to respectfully explain how something works when someone disagrees without sarcasm. I can't compare this forum to others but I do know OPs get help here. The forum was doing fine before I joined and it will do fine when I am no longer a member--none of us are an exception.

Well accoring to the "expert", he back up what I said.

Since the electrical system runs off the alternator how does the battery become a filter for spikes? And if the DME/ECU and other modules protect from spikes why is it such a bad thing to run the engine with only the alternator output if necessary for a short period of time? Rather than reference most vehicles I think we need to stick to what is true of a E53.

I said that the car ran off both the battery and alternator not one or the other. As more electrical load is placed on the system, the regulator compares the voltage that the battery is putting out along with the voltage the alternator is putting out. It adjust the alternator voltage so the battery is always being charged.

What we are failing to take into consideration is not just the voltage but the amps draw when Terminator lost power to his X. He was running at night with all the lights on and if it was in the dead of winter he might have had the blower motor on for the heater and imaybe the rear window defroster.

I have driven a car with a bad alternator on a battery as long as any non essential electrical device were left off including the radio. When the alternator to my PORSCHE crap out on me, I brought a new battery but only drove during the daylight hours. I was able to make the 40 miles trip back home on just the battery.

I understand the alternator regulator adjusts the output to keep the battery changed and provide for electrical systems draw. That seems contrary to the battery is only used to start the engine and supply current to those things that the circuit is completed when the key is turned on. And, that once the engine starts the alternator is the source of current for all electrical systems.

Update
 

Called AAA today driver came out, I said I want it towed home.
Driver said let me jump it its probably your alternator but if it starts you'll be able to make it home, I said I just want it towed. He said drive it around the corner if it workstill it'll be fine you'll make it.


So I left. Speedo abs hill decent all started going haywire.
Car started braking when driving at 50 MPH and dash all went out speedo dropped then I lost power to car and pulled over.

Tow truck ca.e towed it rest of the way home. I'll do test tomarow. It started to rain and has been a long day .

You begin your post with Never in all caps and bold type and then you say it can be done without issues. Then you say it has ruined more electrical components than anything else in history followed by that is an assumption. Confusing again.

Stephen VA stated that it's only an issue if you go and try to put the cable back on with the engine still running.

Yeah as you have learned, never listen to the AAA drivers.

I had to show a AAA driver how to get my car onto flat bed one time. It didn't have a front tow hook so he was just going to use a control arm

[QUOTE=Joshdub;1062615]Yeah as you have learned, never listen to the AAA drivers.


Yes I have learned my lesson haha. My mistake fully on that. But I did tell him multiple times just to tow it to my house haha he insisted on my driving it.

Looks like my tahoe trip is going to be postponed. But I'm glad it failed here not on a snow trip in the snow haha.

Second guy was all surprised that I already had my tow hook on the car ready to be towed haha

now I`m thinking its your alternator ^

[QUOTE=dabenthusiast;1062623]Sucks about the trip man but yeah you are right. Much better to have it fail there than out in the middle of no where

I would not go that far. The real issue are the spikes that are unknown, unforeseen, and mostly unmeasured when disconnecting and reconnecting an active charging system. Examples of this type of damaging spikes are found in loose connectors to modules. The intermittent on/offs FRY the modules pretty quickly. The whole system gets a shock each time there is a disconnect and reconnect of a intermittent Alt for example. This is why all kinds of bad things happen to our vehicles when the Alt starts goes bad besides the battery loosing a charge.
Bottom line: It is NEVER a good thing to disconnect the battery or alternator on a running vehicle. The consequences are always unknown and expensive, and will be hard to diagnosis why a electrical part failed later.

When it comes charging systems, connect all, then start the car, just as you would do with household 110V wiring and devices.

Now to answer a common question that used to come up in tech training classes: "Can you do it just once and not have a problem, just to check a Alternator or battery?" Sure and possibly NO. If it is your car, go ahead. If it is a customer's car, no as YOU will be paying for the repairs and be looking for a job if things go wrong. Techs would argue with the instructor as they "did it all the time" with no issues while the vehicle was in the shop. After being questioned by the instructors all admitted they did not track vehicle returning later for electrical issues. :rolleyes: Just an example of poor shop practices. There are too many tools/testers on the market to test a system without having to resort to that.

All of us agree that checking starting/charging systems is just a series of quick tests to pin point a failure/weakness.

Based on the last posting from the OP, it sounds just like his X5 has been running off the battery due to a Charging system failure to the point the voltage fell below 9.6 volts and things only got worse to complete shut down. Now the battery is in deep discharge and may not come back. Lets hope it does so he can get back to enjoying the Christmas holidays instead of busting knuckles pulling an alternator. :thumbup:

All this discussion about removing the battery cable while the engine is running really cracks me up and is really so stupid.

The only reason this was ever done back in the 60's & 70's is people did not own a multimeter and it was a backs woods way to test for charging.

Why this is even discussed or considered in 2015 when you can buy a multimeter for the price a a few cups of Starbucks and possibly risk damaging or even glitching a module is not even worth the discussion.

Especially when many of the BMW models have a built in Voltmeter and you do not even have to buy anything, open the hood or get out of the drivers seat.

A Voltmeter is really all that is required to get a very good idea as to what is going on with any battery or charging system. Yes, having more than a Voltmeter or tools that can verify AC ripple, measure Amerage and apply a load is all fine and good, but if the charging system or battery can meet some basic Voltage measurements, it is pretty much the case that things are working correctly and in good shape.

So anyone that wants to disconnect their battery cable, go ahead, I believe the more knowledgeable crowd would recommend that this not be done.

:iagree:

NO. The car starts off of the battery, it runs off of the alternator. This has been true since the beginning of time. Back in the olden days, Grandpa cranked the engine over by hand, then a magneto took over keeping the engine going -- just like a lawn mower. Then cars started getting electrical stuff -- lights and such -- and a generator was installed. Grandpa still cranked the car, but the electrical loads were sustained by the generator. Somebody got the bright idea that an engine could be started with an electric motor, but it took an electrical charge to make that happen. Enter the battery. The generator still provided for the electrical needs of the engine, and it also replenished the battery. Eventually the generator was replaced by an alternator -- the generator produces DC while the alternator produces AC that a diode pack changes into DC -- but the idea that the battery starts the engine while the alternator sustains it remains the same.

It is not a good idea in modern systems to unplug the battery while the engine is running, but in a car from before the days of computer controls it was common practice to start a car, then take the battery out and move it to another car so it could be started. Jumper cables make this much easier, but sometimes one might not have cables but for some reason was able to harvest a battery from another car.

The point is, the engine runs because of the alternator, it starts because of the battery. If the battery is gone, starting is lost, if the alternator is lost then engine operations will be lose when the battery goes flat. This can take varying amounts of time depending on the loads and the condition of the battery.

:thumbup:

Just for clarification, I said nothing about charging the battery with the alternator. What I posted is there is no correlation between the life cycle of a battery and that of an alternator.

No one has posted they think it a good idea to remove the battery cables and run the engine on the alternator. No one has said the voltmeter is not the best way to check the electrical system. FYI, I liked the phrasing of your initial posts much better than your most recent ones.

Update
 

Battery out of car tested at terminals was getting a read of 10-11 volts.

Throwing on trickle charger.
Date on battery says Aug 09 ! Haha

Now Im hoping my alternator didn't get killed trying to drive half way home yesterday.

If battery charges enough to start car I will do a running test.
Can i test at the front jump location while running ? Or does it have to be terminals

Or if someone would explain the obc. The online directions are misleading bcz I only have one knob no right knob...
And when I get to the test number for battery volt it goes back to main temp and info

If its that old I'd just get a new battery

:iagree:


Did you go agm battery? And would I be fine getting an autozone or napa auto battery?

Anything is better than the old and mostly dead one you have now. I got the Bosch AGM from Pep Boys since I had a coupon code and a mail-in rebate, you'd be fine with Autozone or Napa, just get the most cold cranking amps you can get.

[QUOTE=Ricky Bobby;1062680]Anything is better than the old and mostly dead one you have now. I got the Bosch AGM


Current one I just took out was bosch. I'dk where I could get one locally. There is no pep boys around me.

I don't have a pep boys near me so I bought an Orileys battery, had more CCAs than Napa or Autozone. Just get the most powerful one that is local and you'll be OK.

Nice. I looked at orielys. Still looking around.
Thanks for the help.

[QUOTE=dabenthusiast;1062681]How about Pep Girls???

try this it works for me everytime. just read carefully.

Instructions to access the hidden OBC functions:
1. Hold Trip Reset while turning ignition key to on position
2. OBC should show "Test"
3. Use Trip Reset to select function 19.0 that unlocks all the features
3. Wait for display to show "Off"
4. Depress Trip Reset for 1/4 second and release it
5. With no delay press Trip Reset several times to select one of the following function s
BMW E46 On-Board Computer (OBC) Hidden Codes
nr example description
1 Car Engine and cluster data
1.0 46nnn Chassis nr/VIN serial number (last 5 digits)
1.1 4nnn K-number
1.2 690236 Cluster Part #
1.3 045210 Coding (04)/diagnosis (52)/bus index (10)
1.4 1200 Week (12)/year of manufacture (2000)
1.5 09_160 Hardware (09) and software # (16.0) of cluster
1.6 Not used
1.7 04__44 CAN-version (04) KI-revision index (44)
2 (test) Cluster System Test - Activates the gauge drivers,
indicators and LEDs to confirm function
3 SI Data
3.0 1098 Used fuel in liters since last SI (Service Inspection)
3.1 0231 Periodic inspection days; elapsed days (since last SI)
4 Momentary Consumption
4.0 0145+ Instant fuel consumption - 0145=14.5 liters/100km
4.1 0018 Instant fuel consumption - 0018=1.8 l/Hour
5 Distance Gone Consumption
5.0 082 Average mileage; 082=8.2 liters/100km
5.1 0536 Calc. km to refuel (momentary distance to go)
6 Fuel Level sensor inputs in liters
6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters
6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters
6.2 0442+ Indicated value (44.2) and tank phase
7 Temperature and Speed
7.0 021+ Coolant/Engine temperature (2.1C)
7.1 130 Ambient/Outside temperature - chg met 5 pts. 125/130/135
7.2 + Engine speed / Current RPMs 1/min
7.3 + Vehicle speed / Current Speed in km/hour
8 Input value in HEX form
8.0 1d0+ System voltage ADC-Value Hex code
8.1 26C33C+ ADC Values HG left/HG right
8.2 0000 ADC Value brake degradation sensor (000=o.k.)
8.3 18C ADC Value outside temperature
9 Battery
9.0 140 Battery Voltage - 140 = UB 14.0v
9.1 242013+?
9.2 074_78+?
9.3 0011+?
10 Not used
11 Not used
12 Not used
13 GonG Gong Test
14 Not used
15 Status cluster I/O-ports (bit codes) 0=low; 1=high
1st-belt contact, seat belt fastened=0; 2) ignition lock contact, key inserted=0; 3) door contact, door open=0; 4) clock button pressed=0; 5) SI reset=0, for reset=0; 6) EGS transmission failure=0
Status Digital Outputs (bits) 0=inactive, 1=active
1) Gong output; 2) Brake warning lamp; 3) Low fuel warning lamp; 4) EGA lamp; 5) seat belt lamp; 6) manipulation dot
16 Not used
17 Not used
18 Not used
19 Lock Status; unlocks functions in range 3-18
19.0 L-On/L-Off Unlock: press button when "L-Off"
20 Not used
21 Software Reset; reset OBC settings
00 End of test

^^^^^
 

Thanks alot. The obc works alot better then having to check volt meter.

New battery at stop is 12.4 and with it running I'm at 13.7
With headlights and heater and radio on.

Am I good or do I need an alternator??

Actually I assume I do.

I started to rev the car. And when it goes above 2k rpm the red battery light came on, then goes off below that.

After raving acouple times voltage dropped from 13.7 to 12.7 then I turned lights and heater again and revved and it went to 11.7 volt....

Give me the bad news

if alternator is working, it should be putting out consistent voltage not erratic, should be a steady voltage like around 13.8 v .nothing lower than 13v. (thats with the engine idling or and revved up.

The voltage fluctuation is a classic example of a failing regulator or the lack of contact of the slip rings and the brushes, which in turn drives the regulator to fail.
Volt flux is a sure sign of alt failure that only gets worse. Tests are done at idle, should read over 13.5 volts and again at 2500 which should show an increase to >14.0v.

Quick test, with one eye on the voltage, bring the rpm to 2500 hold, tap the alt with a soft hammer and see what if any change.
At anything over 85k I would remove the alt, while checking for worn or frayed wires. If your plans are long term ownership buy new, if not buy reman AFTER making the seller test the unit before installing. Some remans are slow to break in and provide full output volts/Amps. As mentioned before some models have water cooled others are just air cooled. When you lay underneath your x you will be able to tell.
Good luck.

^Follow all of Stephen's advice, and I would personally go with a new alt - sooner than later in order to not fry that brand new battery

or screw up electronics in the x5 ,just incase the alt puts out power surge.

Cool ya that is my plan.
Now my problem is if I should get lifetime warranty from autozones new duralast alt.
Or new napa bosch style.

I don't think it is watercooled. Might you know @RickyBobby
If yours and mine are the same ?

And either way can i buy bosch or Valeo type or do I need to take mine out to verify then go buy one?

^If you move the PS reservoir out of the way you should be able to easily see the type of alternator you have, Bosch or Valeo - pretty sure the 3.0's have Bosch's but you should double check -

I don't think m54s ever came with water cooled alternators

That's what I thought. Sucks for the v8s haha

Well I'll check. It's been raining in the bay area the past couple days.

Alternator is all from in the hood no under the car??
I'd so I'll work in rain buto I don't want to get on the wet ground ha

You can do it all from above. Takes about 45 minutes. Remove fan/shroud, remove airbox and intske pipe up to the rubber elbow, unbolt power steering res and move it to the side, undo belt, undo two alt bracket bolts, rear wire retaining nut, unclip wiring harness on back of alt, then pull it up and out in between engine and coolant res.

Easy peasy. Don't forget to disconnect the battery.

Not the 4.8is guys. Ours comes out of the car in 15 min if you are dicking around while doing the work.

I too agree that your alt is on its way out. Especially with the red battery light and a fresh battery.

I have rebuilt my alternator with a new regulator over a year ago. The parts are super cheap, and you can get them from BMW. All I did was spin the shaft with my drill while holding an Emory cloth to the copper pulley thingie that the regulator brushes run against. Cleaned up that pulley and installed regulator. It was super easy.

Pulled it out
 

Finally had some time to pull out my alternator.

It's a Valeo... so Ifar i want a bosch do I just change pulleys?
Or if I buy bosch and it comes with a pully do I need to change anything?
Buy new belts or anything?

Also thought it was weird that tensioner was a bolt not torx or allen

Some pics
 

Alternator

Alternator was abit dirty. Some gunk and dirt/dust on the copper

As long as the new pulley is the same (rib amount and diameter) it'll be fine.

Alright.

Well napa auto didn't have new alt. Only rmaf.

So ordered brand new duralast from autozone. I specified on new and they asked bosch or Valeo so I said Valeo.

New one is shipping from another storeason and I can pick it up tomarow.


Another question. My alternator exit hose wasn't connected to any hose to filter hot air away.

And the alternator I took out said 14v and the ones in all the stores say 12v....

I would bring in the original alternator to have it check so that you will know definitively if it was the alternator. You can replace the common wear item on a Valeo alternator for under $100 bucks (brush and regulator assembly).

Got new alternator
 

Got duralast gold with lifetime warranty.

Done!
 

New alternator is in, voltage is at 14.2 and when everything is on headlights and and stereo and heater it goes to around 13.9v to 14v



Didn't take the fan or fan shrout or any of the radiator hoses off.

how long did it take ya ? just curious.

You have some skinny ass hands to release the belt tensioner without removing the fan.

Started around 4 and ate dinner by 5...
I had a friend trying to release tension while I pull belt on. No room at all!
Finally I just released tension and slid belt over the alternator by myself.
Very tight spaces but didn't want to have to fill coolant and I didn't have tool to take fan off.

Happy new year !!!!! :D I'm glad I go the car running before the new year! I will go to lake tahoe soon now!

Congrats! Happy New Year to everyone

glad you fixed the problem, still can`t beleive you didn`t have to take the fan off though.

Ya it was tight, mainly finding a short socket is what worked best. Then long bar so my hands didn't have to be down there besides putting socket on the tensioner.

When driving yesterday when I came to a stop my rpmschedule would kinda go up and down from idle, kinda like a vacuum leak.

But nothing is wrong with the intake or manifold..