Question regarding the dreaded battery drain issue

[Superhiro]

Haha thanks man Umm I'mnot familiar with Elk Grove but isn't most of CA nice and warm and NOT very snowy hehe.

Back on topic though, I read that the error I am having could be fuse related as well and thought maybe picking up something to test would be worthwile. Where could I pick up a multi tester and how much do they usually run?

[Weasel]

Originally Posted by teamgs

Thanks, and welcome to the board! Your car looks SWEET!

I think I may just leave the fuse out, as the wiring diagrams show that nothing other than the phone system is on that circuit, and we didn't get that option when we bought the car.

Now, on to fixing the malfunctioning windshield and headlamp washer pumps/circuits! Winter is around the corner, and keeping the windows and headlights clean is critical on our weekly trips to the snow.

Gary

My question is if there is no TCU installed, why does that circuit have a draw? I have once the connector for the TCU get wet from a small water leak and corroded between contacts. Since all X5's are prewired for phone, it might be worth checking the connectors for damage/corrosion. Just a thought...

And for the washer pump, the pump motor itself is a common fail point. If you look at the washer pump and there is any signs of leakage/corrosion at the bottom of the pump, thats likely the only problem. Good luck!

[msammy]

Originally Posted by teamgs

Well, the battery stayed charged at 12.65 volts this morning, and this was after all my drain testing last night and no recharging.

So....I think I have found the general circuit causing the issue, but now to find out what is causing the drain. At least I can drive the car without worrying about a dead battery.

When I find the issue, I will post back.

**EDIT**

Looking at the wiring diagrams, it appears to me that nothing else is on the circuit in question but the phone system. Since we don't have any installed phone, I am tempted to just leave the fuse out, and call it "good"

What do you think?

Thanks again!

Gary

I'd say just leave it out to use the car, but it's an intriguing problem that I'm sure you'd like to understand! Just double check to make sure that circuit isn't used for abs, dsc or any other safety feature - if not, I’d play around with that fuse to see what's drawing that kind of juice. It's good that you stuck with it and figured out which fuse to pull - I've done that job myself and it took many many hours and lots of patience (waiting around to see if the car would enter sleep mode after each fuse pull). If you figure out the problem, please post an update!

[teamgs]

A decent multitester runs around $50. A really good one can run in the neighborhood of $200 or more.

You basically want one that can read volts (AC/DC) amps (AC/DC usually 10A max) and Ohms (Usually continuity is used. I.e. an audible "beep" when a circuit is completed). I prefer a digital meter, and one that can also read milliamps.

There are many people and tons of data you can ask/read regarding what meter is the "best". I am not an expert on that. I have a couple of them, one was a relative cheapie from Radio Shack, and the other is a better unit, received as a gift when I purchased my Soldering Station. you can get them from Radio Shack, Home Depot, etc.

Regards,

Gary

[teamgs]

I think that the defective circuit may not be drawing 4 amps, but drawing just enough to not allow the car to sleep.

I guess my next step would be to test the current flowing through that circuit at the fuse.

Regarding the washer pump, I have already burned out one, and am hesitant to install the second replacement unit. There seems to be 8.5V to the windshield pump, even when it isn't active. I am wondering if that is normal, or is what burned out the first replacement unit. I posted a question about this many months ago and received no reply. I need to go across the street to the inlaws, who have an 04 X5, and test their system.

Oh yes, regarding California: We live in the Central Valley, just south of Sacramento. 90 minutes to the ocean (San Francisco) and 90 minutes to the mountains (South Lake Tahoe). We have a place at the base of the Heavenly Valley Ski Resort, so we are up many weekends in the Winter. Having washer pumps that function are a necessity.

Regards,

Gary

[Weasel]

Originally Posted by teamgs

I think that the defective circuit may not be drawing 4 amps, but drawing just enough to not allow the car to sleep.

I guess my next step would be to test the current flowing through that circuit at the fuse.

Regarding the washer pump, I have already burned out one, and am hesitant to install the second replacement unit. There seems to be 8.5V to the windshield pump, even when it isn't active. I am wondering if that is normal, or is what burned out the first replacement unit. I posted a question about this many months ago and received no reply. I need to go across the street to the inlaws, who have an 04 X5, and test their system.
Gary

There should be no voltage when the pump isn't being activated... That might lead into the bigger picture of a hidden electrical problem in your vehicle. Look deeper into the wiring schematic for the washer pump supply/activation circuit. (I can't from home, need to be on explorer w/java apps, I'm on firefox on a mac...) You need to find what is keeping that voltage to the pump. And maybe find what is using voltage on an "unused" circuit... Has there ever been any water in the lower box the battery is in by chance?

[teamgs]

Hey Weasel,
Nope, no water ever in the battery box. I will definitely be checking into the pump issue. Gawd, I hate electrical problems.

Gary

[03BamaX5]

Originally Posted by teamgs

Well, the battery stayed charged at 12.65 volts this morning, and this was after all my drain testing last night and no recharging.

So....I think I have found the general circuit causing the issue, but now to find out what is causing the drain. At least I can drive the car without worrying about a dead battery.

When I find the issue, I will post back.

**EDIT**

Looking at the wiring diagrams, it appears to me that nothing else is on the circuit in question but the phone system. Since we don't have any installed phone, I am tempted to just leave the fuse out, and call it "good"

What do you think?

Thanks again!

Gary

I pulled fuse #74.. Problem solved.

I do not have the factory phone option either and I can't find anything else on this circuit so its now removed. No dead battery in over a week.

GREAT FIND!! Thanks for the help.

Brandon

[teamgs]

You are most welcome, Brandon! Glad it worked for you.


Gary

[Seros]

Hey guys, would love to know if you found this current draw (Fuse #74) to be an intermittent one. I am having real issues with a current draw that happens randomly (once a week) which makes tracking it down even harder.

They have replaced the amp, radio module, FSU, check ECU for moisture.... it about to go to BMW to get to the bottom once and for all.