Hello there and welcome to the BMW Car Club of America.

If you are a BMW CCA member, please log in and introduce yourself in our Member Introductions section.

And the Next Problem Is: Alternator Not Charging

Discussion in 'E30 (1984-1993)' started by BMWtyro, May 22, 2012.

    • Member

    BMWtyro

    Post Count: 22
    Likes Received:0
    When a working alternator (in this case, a Bosch 80A) is removed from an M20 (in this case, an M20B20) for a couple of months, detailed (lightly cleaned, not disassembled, panited aluminum, rubber mounting bushings replaced), reinstalled and does not charge, what is the likely culprit? And how do I test it for output without damaging it?

    This car needs to be dependable by early Thursday morning . . . so if the problem can't be resolved with the current alternator, then will the one from wifey's '87 325e interchange? I hate few things worse than playing "musical parts" with my cars, but . . .

    Jeff Dreibus
    1984 320i 5-Speed
    1987 325e Automatic
    Too Lazy to Post a Real Sig
    • Member

    MGarrison

    Post Count: 3,966
    Likes Received:254
    Perhaps use realoem.com to compare parts numbers - same part number, then no problem. Different part number, then the question is, what's the difference. Bentley manual I think details testing procedures, including the voltage regulator. Might be worthwhile to get the battery tested, if it was marginal at project's beginning, it may have gotten to the point where it won't hold a charge anymore. Only other thing I can think would be the probably unlikely oddball possibility of paint somehow getting where it shouldn't have and affecting the alternator's operation - but, that seems unlikely to me.
    • Member

    BMWtyro

    Post Count: 22
    Likes Received:0
    Interstate battery is one year old and never had any problems.

    I will see if I can test it and, failing that, check the Penske site.

    Thanks.

    Jeff

Share This Page