Gen light on ,ignition off

Discussion in 'Sparky's corner' started by Dwayne B, Mar 12, 2018.

  1. Dwayne B

    Dwayne B Well-Known Member

    Late fall befor I parked my 72 skylark for winter, A couple of times the Gen light would stay on ,with ignition switch off.
    I looked in my 72 service manual ,and it said I had A positive diode shorted,locate and replace.It was saying power goes from gen light to voltage regulator,and to alternator. I was wondering if my voltage regulator may be going bad,wanted to see what y'all thought .
     
  2. mrolds69

    mrolds69 Still restoring!!!

    Was the gen light bright or dim? I'm thinking maybe the ignition switch needs adjusting.
     
    OHC JOE likes this.
  3. Dwayne B

    Dwayne B Well-Known Member

    I can't really remember, its be A few months since I had it running .
     
  4. OHC JOE

    OHC JOE BUILDIN A 1970 GSX CLONE

    I'd say ignition switch
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    From the 71 Buick Chassis Manual,

    AltLightDiag.JPG
     
  6. Dwayne B

    Dwayne B Well-Known Member

    From what Larry posted ,that's saying maybe the alternator. Larry I didn't see that page in my book,I just got mine the other day. When it first happened I thought maybe ignition switch .

    I hate A electrical problem, can be mean to figure out.
     
  7. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    It's in there. Look in the Generating System chapter. Follow the diagnosing charts or instructions. That's why you bought the book.:)
     
  8. Dwayne B

    Dwayne B Well-Known Member

    OK thanks Larry
    I was just seeing if anyone else ever had this problem.
     
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I guarantee lots of guys have had that problem.
     
  10. Dwayne B

    Dwayne B Well-Known Member

    That's part of driving these old cars, makes ya scratch your head some times.
     
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    :D:D They are still infinitely easier to diagnose than modern cars. Old cars are very simple electronically compared to late model cars.
     
  12. Dwayne B

    Dwayne B Well-Known Member

    Yes ,they are.
    Larry I have read the chapter in my shop manual ,two times that you said to look.
    I'm starting to understand the generating system A lot better .The book really brakes it down very good.
     

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