Battery and charging system experts please chime in

[GenXer]

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]

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.

[MPDano]

Yup, go the cheaper route first. Yank the battery out and have it check at your local Auto Parts place. If your battery is good, then move on to the Alternator. Unless you know what your doing as far as replacing parts inside the alternator, leave that for the pros.

Heres is my advice which has cost me a load of headaches and losing more than money that it's worth (I ended up taking the local rebuild place to court and won).

Never, ever, never, ever buy a Rebuilt Alternator. Buy a New one or Remanufactured one from a reputable place. There is a difference with Rebuilds and Remans.

[X5girl]

Sorry, you should not accept that it is hit or miss, that is so amateur. It is really not that difficult to diagnose a fault that is present, only intermittent faults are difficult because if there is nothing wrong when the car is tested then there is nothing to find.

An alternator and a battery can both be tested on and off the car.

It sound like you would be better off going to a dealer and getting the correct dignosis first time rather than financing your indie's guessing game.

X5Girl, xxx