View Full Version : Alternator?.....i think

03-23-2009, 04:36 PM
so after it's been sitting for about 5 months...i took my 89' 325i out for a spin a couple days ago.

the battery was dead, so i jump started it and it started up on the first try.

but just now i tried to start it again and nothing...no power, so i got the jumper cables out and it turned over but as soon as i disconnect the cables the car turns off.

i tried leaving them on for a few minutes and same thing...as soon as i disconnect the negative (-) it turns off.

Is this because I have a shitty old battery or will i need a new alternator?

03-23-2009, 04:43 PM
Try charging the battery first. it may need to be tricked into charging if it's absolutely dead. but seeing you drove around with it; I don't think that's the case. 2nd. interesting that you have this experience because I suspect mine is the same but not that severe.
I charged my batter in the car a few times and the charge holds for about 1-2 weeks. doesn't go completely dead but there is either a draw from one of the accesories or my alt isn't doing it's job completely. BMW tech friend of mine suggested that I rebuilt the alt. He says it doesn't always show up right away the alt is not charging adequately.
if you got over 200k on the car the brushes may be worn. I was getting 10.9vlots with all acc. on instead of 12-13. just something to consider.

no point putting a used one in because you'll probably run into the same thing not to far into the distant future.. rebuilt is about 60-100 depending where you go.

03-23-2009, 04:48 PM
This is the same thing with my car after i stored it last winter. As mentioned above try to charge the battery first.

03-23-2009, 04:53 PM
^^^ did that work for you? or did u have to get a new one?

03-23-2009, 05:01 PM
yea the car is fine now i started it after storage with no problem with the same battery and alternator

03-23-2009, 05:05 PM
thanks guys...ill give that a shot

03-24-2009, 06:57 PM
So it turns out that the alternator is no good. Ceeker mentioned it's 60 - 100 to get mine rebuilt.

Anybody know a shop around the Islington and 401 area where I can get this done?

03-24-2009, 07:06 PM
battery is done for.. just get a new one and you're good =)

03-24-2009, 07:10 PM
a certified mechanic told me it was the alternator...he's my cousin so i don't think he's trying to screw me

03-24-2009, 07:57 PM
get a volt meter and see what it says when car is running. Should be 12v if the car is off. And 13-14 running. If its showing less then 13v when car is running alternator is bad.

03-25-2009, 11:26 AM
^^^ thats what my cousin did...i didn't ask him what the volt meter read but he says it's the alternator

anyone kno where i can get my alternator rebuilt or buy one?