Results 1 to 9 of 9

Thread: gm alt. wiring

  1. #1
    RedRocket
    what do I do with the white wire? A mechanic drew a diagram for me which isn't right. It shows running the white to the i on the ign. switch. Now the motor doesn't shut off. ( i can't afford to have it idling until I use it again) I ran a separate distr. switch but now I want it done right. The red is looped back to the power on the alt.

  2. #2
    Senior Member
    Join Date
    Feb 2009
    Posts
    2,626
    The alternartor is wired correctly. Some GM alternators require a diode in the "white" wire you describe. This prevents current feeding back from the alternator into the ignition. A 100volt/1 amp diode is what MSD recommends (they reference this issue in their installation instruction). Works even if you don't use an MSD ignition. Diodes have a small mark on them. That end should be towards the alternator.

  3. #3
    FoMoCo
    I did that once on a Buddys Boat, we ahad the 2 wires Backwards on the Alt!(should be 2 blade type termilnals) One activates and starts the Alt to work. If that is getting direct Battery, it will never shut off!!

  4. #4
    LeE ss13
    Run that white wire to the small terminal on the starter solenoid opposite the one that runs to the starter switch. It should be closest to the block. This only works if there are no wires there now. Old point distributors ran a wire from that terminal to the + side of the coil to by-pass the balast resister when you were cranking the engine and the voltage dropped a bit. If is not connected to anything else but the white distributor wire, it will energize the alternator when you and cranking the engine and start charging. When you stop cranking, it will disconnect from the ignition circuits so you can shut the engine off with the switch.

  5. #5
    wet77
    Get rid of that complicating mess and switch to a GM 1 wire
    Wire from alt to + side on battery DONE
    Ran like that for 3 years no problems
    Alt cost me $60 and always have full power to the distributor and starter

  6. #6
    Joe B
    Im with Oldsquirt. Put in a diode since you already have the alternator installed. Radio Shack has diodes for $.50. Just solder it in.
    joe

  7. #7
    GofastRacer
    Originally posted by wet77
    Get rid of that complicating mess and switch to a GM 1 wire
    Wire from alt to + side on battery DONE
    Ran like that for 3 years no problems
    Alt cost me $60 and always have full power to the distributor and starter
    Ditto!..

  8. #8
    Infomaniac
    Originally posted by FoMoCo
    I did that once on a Buddys Boat, we ahad the 2 wires Backwards on the Alt!(should be 2 blade type termilnals) One activates and starts the Alt to work. If that is getting direct Battery, it will never shut off!!
    O yes it will LOL
    Customer called me in a panic after installing his new alternator and it would not shut off. Boat was still running.
    The MSD threw major sparks while he carried out my instructions of yanking the coil wire off.

  9. #9
    RedRocket
    Thanks for all the info fellas, I guess I have two low-buck solutions. Alternators aren't that cheap in Canada.We get screwed buying parts!

Similar Threads

  1. MSD wiring...
    By BrendellaJet in forum Gear Heads
    Replies: 11
    Last Post: 02-12-2007, 02:07 PM
  2. JL amp wiring?
    By jbone in forum Audio
    Replies: 1
    Last Post: 06-19-2006, 06:26 AM
  3. Wiring ?
    By Taylorman in forum Jet Boats
    Replies: 15
    Last Post: 07-16-2005, 02:08 PM
  4. need help wiring mpi bbc
    By BLOWNDEAVER in forum Out Drive
    Replies: 0
    Last Post: 07-01-2005, 08:11 AM
  5. Wiring help
    By JEThro in forum Jet Boats
    Replies: 0
    Last Post: 06-14-2005, 04:46 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •