Electrical Woes - Bad Alternator/Voltage Regulator

rhusbands · #1 08-01-2015, 02:59 PM

I have a 2003 X5 3.0 with 183K on the clock. Last week, my battery light began coming on periodically. It has done so three times. I noticed that it only comes on when I am at WOT and revs approach redline (under hard acceleration). Once revs drop back to normal cruising speed for a few minutes, the battery light goes off. My thought is it is probably the voltage regulator, so I am going to get a replacement and change it out. Will probably get a new battery as-well. Any caveats I should be aware of?

Just FYI... I've only had the vehicle for 4 months, and have no maintenance history on it (other than what I have done... Valve Gasket, Oil Filter Housing Gasket, and Crank Case Vent Valve).

Thanks,

-Ronnie

rhusbands · #2 08-03-2015, 09:38 PM

Thanks fella's... I will look up a reman (and go by an auto parts store and have them check the battery)... On another note, the negative terminal is broken. What I mean is it looks like someone over tightened the locking screw and cracked/broke the terminal clamp. Fortunately it's the ground terminal which should be both inexpensive and easy to replace, but I haven't looked yet. Any experience with it?

crystalworks · #3 08-04-2015, 12:31 AM

^Negative terminal is extremely easy... and as inexpensive as you want it to be. I've used 0 AWG or 4 AWG stereo wire with a good battery terminal and ring terminal on each end in a pinch. Since I used to do stereo installs the cost was $0. A used OEM one on Ebay is also an option...

FYI OEM part number is: 61116919976 and is $28 at ECS. I'd probably go that route on the X5 were I to be in your shoes.

crystalworks · #4 08-02-2015, 09:17 AM

Quote:

Originally Posted by trader4

Personally, given the work involved, I'd put in a rebuilt alternator.
That's what I did when the one here failed. Has the battery been
tested? I agree it sounds like the VR/Alternator, but the battery
is easy and you could start there.

I agree with Trader.

Run to Oreilly's (or ChinaZone if you prefer) and ask them to check the battery and charging system. Unfortunately since your problem is intermittent... the alternator might check out okay. But it will at least rule out the battery as a problem.

Then, since it definitely sounds like an alternator crapping out (mine is doing what you describe as well but for a different reason) I'd also go with a rebuilt/reman alternator. Fortunately you M54 owners have it a little easier in terms of replacement than us N62 owners.