1991 325 Charging Problem

[Rajun Cajun]

My '91 325 M Technic has a charging problem and the symptons are simular to a post on the DIY as the dash trouble lights blink dimley and the electronics act crazy. I pulled the alt out and checked the brush length and they were 12mm long which is ok.
I have a brand new battery installed but have the same problem even when fully charged. The alt is a Valeo # 2541114 and I'm not sure where the best place to buy a new one would be.
Has anyone had this problem or can help point me to a good parts place I would appreciate it.

Thanks,

Andy Johnson

[AndrewBird]

Measure the voltage at the battery with the car running. Should be ~14v. With the car off, it should be at least 12.5v.

Even if the brushes are in good shape, the voltage regulator might have died.

[Rajun Cajun]

I did that once but don't remember the exact voltage value but don't think it was 14V maybe 13V.
I will put the alt back together and measure it again.
Do you know where I can get parts for a Valeo alt?

Thanks,

Andy J

[Rajun Cajun]

I reassembled the alt and had 14.2V with the engine at idle. At 2000 rpm the voltage dropped to 13.2 and headlights on 12.8V
I checked with my O scope and had no AC ripple voltage so I will assume the diodes are good.
Time to try and find a voltage regulator. Thanks for the help

Andy J

[reelizmpro]

Hey Andy, we spoke on bimmerfest.com. Sounds like a voltage regulator issue. Most of the time, its worn brushes. Check the belt tension as well.

[Rajun Cajun]

Hey Brad, how have you been? It's been a while!
I pulled the voltage reg out and checked the brushes, they were 12mm long. I'm with you though as I think it's the voltage reg.

Do you know where I can get parts for this Valeo alt?

Thanks, Andy