Alternator Failure

[sscaro]

Yesterday the red battery icon lit while driving. I made it home & hooked up my battery charger to make sure I would get to the shop the next morning - my charger is one of those that charges until full and then goes into "top up" mode. It also has an alternator test, which tested the alternator as good after the battery was charged.

This morning I started the X and there was no battery light. I went to my indie shop and he said that the alternator is the only thing that will trigger that light. He also said that even though the light went out, the fact that it went on in the first place means there is a problem, and we can't know when it would reoccur - he recommended a replacement to avoid failure at an inopprtune time.

I went ahead & replaced it, but wondered what you guys think about his assessment - I've known him a while and have always thought him trustworthy.

Did I do the right thing?

[fast4d]

what's the voltage with the engine running? how many miles?

[primetime]

How much did the replacement cost?

[BrianX54.4is]

My alternator died last Christmas week. My indie sent it to a re-furb specialist but they said it was beyond repair. The main BMW dealers had no alternator in stock (there are no spurious ones for this car) and I was without the car for whole Christmas waiting for a shipment from the UK. Cost me Eur1000 for the parts and labour and a mate hooked me up with the loan of a 7 seater mitsubishi for the week.

You might have been a tad previous in doing the replacement without first determining what the exact fault was since your charger indicated good and the warning light went out (it might have been as simple as a bad power or ground connection or the voltage regulator - or even a loose drive belt!). All irrelevent now of course. How much did he charge?

[sscaro]

He charged $515 total. The X has 45K but is out of warranty - Problem was I didn't want to have to wonder when it might go & leave us stranded somewhere.

[604x5]

Ya you did the right this cause my did the same thing 3weeks ago and i had to find out thte hard way, as i was goin to the shop my car died and had to get it towed. all in all cost me about 900.

[CharlieHustleX5]

If the battery light indicator went on in your cluster, your charging system was not working properly. In other words, your alternator was probably on its way out.

It doesn't surprise me...I have an 04 X5 3.0i and my battery light came on @ 61k miles. Turned out the voltage regulator on the alternator wasn't accepting a charge. I just picked up an OEM Valeo Alternator for a real good price and swapped it.

I think you did the right thing. When my battery light went on, I took it to the dealer just to get a rough estimate on how much it would cost to repair. The SA gave me a general estimate of $1380 to replace the alternator, 2 belts, and 2 pullies ............ So I turned around and ordered the parts online and did the work myself for a little over $300.

[Bimmer360]

^^ good for you! Autohausaz is selling it for $397 right now. And yes, DIY is highly recommended.

[asiax]

i've been having a problem with my battery light coming on for some time now. it usually comes on when i start up after a stop or when idling for an extended period. will only go off if a then drive for an extended period.

have had it checked twice at the dealers who can't find anything wrong. i suspect the alternator's going but its still under warranty so i want them to replace it...if i take it in again, what kind of test should i get them to perform and what kind of results should i be looking to see?

[CharlieHustleX5]

Originally Posted by asiax

i've been having a problem with my battery light coming on for some time now. it usually comes on when i start up after a stop or when idling for an extended period. will only go off if a then drive for an extended period.

have had it checked twice at the dealers who can't find anything wrong. i suspect the alternator's going but its still under warranty so i want them to replace it...if i take it in again, what kind of test should i get them to perform and what kind of results should i be looking to see?

I would bring your car in, have a service advisor walk with you to the car, start up the engine, and turn on EVERY SINGLE accessory you possibly can. I noticed that when my alternator was going out, the red light would come on as soon as I turned on my headlights, and then turn off after driving with them off. SO if you're planning on having the battery light illuminate when you get to the dealer, drive there with your headlights on, radio on, rear window defroster, whatever else to make that alternator light go on so you can have them replace it out for you.

I dont think there's any test you can tell them to perform... It would almost be like telling someone how to do their job, and I dont think they would take it too well.