Failed/failing alternator?

[telijah]

Started yesterday, but the car seems to be clearly running off just the battery alone. My rdio went first, then slowly the ABS light, then the DSC light came on, HIDs started flockering, THEN the battery light came on. I pulled over and checked the engine bay, belts looked fine.

I hooked up my jump box for a while and let it charge the battery. Started up and drove fine for a while. The on my way home, the same symptoms started coming back. So I am not sure if the alternator is completely roasted or partially as the amount of time I was able to drive was about 30 minutes. The battery is only about 2 years old. Calling AAA to come out and see if they can even test the battery, otherwise I am towing it to my indy as, aside from oil changes and filter swaps, I have no time or place to do any DIY at the moment.

[yod88]

run the alternator check through the OBC...see how many volts its outputting

for reference: http://www.youtube.com/watch?v=3AajTPsJyPI

[Johal E32]

I picked up my alternator from autohausAZ. They charged 199 (I think) for a re-manufactured unit, but it looks brand new and it comes with the voltage. regulator.

I DIY'd mine in about 2 hours. I could probably do it 1-1.5 hours next time, the alternator itself is kind of stubborn to take off, I had to use a hammer :shifty

[telijah]

Test showed the battery with car off just under 12, turned the car on and the volts initially were at 11, then after a couple minutes dropped to as low as 9, so AAA has just left my place with the car :(

[Dave1027]

Classic symptoms of a bad alternator. At least you had the jump box to get you home. When it happened to me I had to pay for a tow.

[telijah]

Yeah, shop already called me and confirmed it was the alternator. And of course mine is the 120 amp (more $).

[brettbimmer]

Just replaced an alternator in my E36 two weeks ago. Similar symptoms to what you described, but I noticed faint battery light first, as well as whining noise at alternator. Swapped it over a few evenings, and car has been great. My battery was also about two years old. How many miles on your car/alternator?

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[telijah]

Car has about 150k, and I have no reason to believe the alternator has ever been replaced, so likely time to change it anyways.

[LivesNearCostco]

If you have Bosch, make sure you know which one. I think the E46 got one Valeo abnd two Bosch 120A alternators. One Bosch has a rectangular plug and cooling duct, other has an oval plug and no cooling duct. Maybe all the ZHPs have the one with oval plug and no cooling duct? And the 3 use different width (thickness, not diameter) pulleys.

[SoCalZman]

run the alternator check through the OBC...see how many volts its outputting

for reference: http://www.youtube.com/watch?v=3AajTPsJyPI

Person in vid was showing the volts when the car was off. Could this be used to test the battery as well instead of using a meter?

[danewilson77]

Person in vid was showing the volts when the car was off. Could this be used to test the battery as well instead of using a meter?

Yes

[llll1l1ll]

It can also be used to make sure your alternator is putting out.

Heh.

Putting out voltage that is.

[quikryptonite]

Those were the telltale signs when my alternator went kerplooie. I bought a remanufactured Bosch alternator from TMS and then sent in my bad one and they refunded me about $75. I was able to install it myself with some generous help from DW. I second what LivesNearCostco said, I had to pull mine out to determine which kind I had.

[telijah]

The indy I took it to is a specialist, no chance he would have gotten the alternator wrong. I am about to go and pick it up actually.

[quikryptonite]

I was just confirming what LNC said for those who may see this thread in the future. I wasn't trying to say that your mechanic doesn't know what he is doing.

[telijah]

Its cool, good looking out. Thanks for everyones help!

[SoCalZman]

Yes


Excellent. Glad our cars has all this neat stuff built in. Now I wont have to suffer the indignity of having to ask my roommate how to use the meter he lent me to check my battery (I have never used a meter before). :)

[echo46]

As stated classic symptoms of alt failure. ALso liked the OBC tip. I just always use a meter. Glad you got it straightened out.

[telijah]

Why cant I get the dash test to work again? Once I get it to test group 9.0, I let go so I can see 9.1 but it instead goes to the regular screen with odometer...

Anyways, also found the source of my slow coolant leak... one of the end caps on the radiator... fml.

[echo46]

Was the end cap cracked?

[telijah]

Yes, but very very small.