Battery and charging system experts please chime in - Page 5

MPDano · #1 10-06-2009, 12:47 PM

Yes, that does sound like a possibility as far as X5 Home Mechanics.

Also, very possible on the connections. There was one area I am going to recheck before i button it all back up. There was a plastic box that the connector behind the Alternator routed to. You also may want to check there.

MPDano · #2 10-06-2009, 09:17 PM

Replaced Alternator with a Remanufactured Bosch 140 Amp from NAPA. All is charging fine. Got almost 14 volts when idling.

toddjoh · #3 02-19-2010, 11:33 PM

The Amp rating of 120 and 140 indicate the maximum output that the alternator is capable of. It can only put out that maximum for very short periods. It's better to have excess capacity than to operate in near max. That said the 120 will likely have no problem as long as your not running a lot of aftermarket lights, stereos, etc. that might further tax the electrical system.

X5 Meister · #4 02-21-2010, 02:16 AM

There is an SIB discussing a a faulty diode in the alternator regulator on E53 X5's with the M54 engine. Basically you need to replace the voltage regulator and not the alternator.

SIB 122205

GenXer · #5 02-22-2010, 08:02 AM

Thanks for the info, but I have an 01 with the 4.4 and 150 amp alternator.

bmwbmwfan · #6 05-15-2010, 07:59 AM

HELLO!

Two days ago I noticed the battery light would come on upon starting the car an then go away within 10mins of driving. Then yesterday, noticed again the blasted thing....drive all morning no problems.

Getting back from work, I see the battery charge light come on again, but with many friends (all of the warning indicators came on), and car stalled 30secs after.

I was able to use the momentum of the wheels to fortunately roll it near a Mr. Lube shop. The guys there tested the battery for me an obviously it was very low. They were convinced it was the battery...I was not.

In my case, does this not sound more like the alternator?? Please help.

ika · #7 05-15-2010, 10:27 AM

its alternator problem. before replacing whole alternator, check Alt Regulator Module which is located on Alt.

X5girl · #8 05-15-2010, 11:21 AM

Yes, almost certainly the alternator. They just want to sell you a battery.

GenXer · #9 05-15-2010, 02:15 PM

Could be alternator or battery, both should be checked out, if found to be fine, I would look to ignition switch, as it will cause a multitude of weird problems.

I've been through two alternators, two batteries and a belt tensioner, realized Indy was guessing also as to what was causing the flashing battery light. I've got an 01 4.4 X5 with 130k, so it probably needed those parts anyway, but the problem persisted. New wrinkle, last week X didn't want to start, no crank, nothing, even though battery was fine with alt delivering proper volts, finally started after a few min of trying, ran fine, but battery light has not stayed on or flashed since while driving, so I'ved decided to replace ign switch this week, can't hurt, it is a cheap easy fix, about $70 for part, will update once completed.

Bottom line, I don't think anybody has a clear cut fix to BMW electrical issues, basically it's just hit or miss.
Alex

bmwbmwfan · #10 05-15-2010, 02:29 PM

Wow, what a pain you went through and technically still are.

I didn't know that the voltage regulator is separate from the alternator - I thought they always came together. My car was towed on flatbed to a different shop.

I saw someone elses posting about the ignition switch and was really confused how so. But then again nothing always is crystal clear.

If I purchase higher Ampage for the alternator to play it safe, it should be okay right? I did this before on my older car E32.