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FJ40/SBC elec question

Discussion in '40- & 55-Series Tech' started by eelson, Jan 27, 2004.

  1. eelson

    eelson

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    Well, the year-long SBC conversion is finally almost complete! I finished up the wiring over the weekend and turned the key...and the bastard started right up! Only thing is, it won't turn off by the key. That's the last problem I thought I would have. Has anyone had this problem before, and does it have anything to do with wiring the 40 to the SBC? Maybe I missed something?

    Thanks!

    Eric
     
  2. Bret

    Bret

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    Did you put a diode in line with the GM alternator? I think that will cause that problem.
    Good Luck
     
  3. Plowboy

    Plowboy

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    If you are running a gm alternator with an external regulator. There is one wire that was on the factory setup that you don't use. It feeds back through the key and will run your battery down. Only bad thing is, IT was so long ago that I did the conversion, I don't remember which wire. :-\
     
  4. Landpimp

    Landpimp

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    or use a light it does the same thing, just put in line

    [quote author=Bret link=board=1;threadid=10695;start=msg96066#msg96066 date=1075237052]
    Did you put a diode in line with the GM alternator? I think that will cause that problem.
    Good Luck
    [/quote]
     
  5. Eskimo

    Eskimo SILVER Star

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    I accidentally wired my HEI's hot wire into the charge wire, and it did the same thing.
     
  6. eelson

    eelson

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    So here's how I wired up the GM alternator (internally reg.) First, I have the big white/blue wire going to the BAT terminal. Then I connected the small black/yellow wire and small white/green wire together from the old regulator (on driver's side). Then I connected the other end of the white/green wire (on the passenger side) to the #1 terminal. Again, this is also connected to the black/yellow wire on the driver's side. Then I just connected a jumper wire from the #2 terminal to the BAT terminal. I don't have a diode or light anywhere, or an HEI. Should I add a diode or something?

    Thanks a lot!
     
  7. theo

    theo

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    Add either a light or a diode. The light goes in-line where you connected the wires from your old regulator. I ran that line to the dash and put in a $4 red dash light.

    The diode goes in-line with the power wire to the alternator (I think. Someone correct me if I have that wrong.) Diodes are "electricity gates" that only allow current flow in one direction. The idea is to stop current from flowing out of your alternator and feeding back into the ignition.

    Common problem on the sbc swap. Welcome to the club.
     
  8. eelson

    eelson

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    Thanks for the advice guys. That's kind of what I thought I might have to do. I'm sure I'll see an assortment of other bugs needing to be worked out.
     
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