72 won't run

Discussion in 'Technical' started by Hairy W Bush, Mar 19, 2016.

  1. 70GreenMonster

    70GreenMonster Member

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    When we installed the DUI in my son's 65Falcon we ran a wire straight off a new ignition switch. We did not use any part of the existing harness. And we had to set the timing WAAAYYY past factory, I think it was at 14 degrees BTC.
    170 with DUI-Weber-small log.jpg
     
  2. 70GreenMonster

    70GreenMonster Member

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    We did not change anything on the solenoid, just disconnected the ign. "on" wire from back of switch in dash. and plugged in a new wire. (the red one in the picture above).
     
  3. Hairy W Bush

    Hairy W Bush Member

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    and why did you have to do that? were you having the same problem as I am?
     
  4. 70GreenMonster

    70GreenMonster Member

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    It was in the instructions with our dizzy. We had no problems at start up.
     
  5. 70GreenMonster

    70GreenMonster Member

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    The instructions said to find a constant 12v+ from the ignition switch. So we went straight to the switch.
     
  6. Krazy Comet

    Krazy Comet Tom

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    Easiest fix is going to be find the red/green wire at ign sw plug on column, splice in and run another wire from that point to your dist...

    OR you can use the red/green to trigger a relay that's powered by battery, the resistor doesn't drop enough current to stop the relay from operating... Because I installed a additional fuse box to power E-fan, head lights, ign system etc I chose this route, relay is triggered by red/green wire, resistor wire is still connected in dash harness......
    [​IMG]
     
  7. 70GreenMonster

    70GreenMonster Member

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    A much more complicated solution.
     
  8. Hairy W Bush

    Hairy W Bush Member

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    I was thinking about going to the switch that also, but the problem is that wire is thinner than what's supposed to go to the HEI.
     
  9. 70GreenMonster

    70GreenMonster Member

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    I used 12 gauge copper wire off a spool from the parts store and crimp on female spade terminals.
    took 10 min.
     
  10. Krazy Comet

    Krazy Comet Tom

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    That wire is the feed to stock ign, if resistor were in engine harness you'd have been using it... If you want larger gauge wire go with the relay...

    Maybe for you, relay was easy to connect, red/green wire to power it and ground, plus power from battery side of solenoid... AND I didn't have to go poking around under dash to connect it... Can be done without the fuse box, but I choose to have power for almost everything under hood from that point...
     
  11. rthomas771

    rthomas771 Member

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    Whats up with the Scotchlok on the wiring harness? Those thing should be against the law. Tell me that those are not household wire nuts in the wiring harness also? If your're lucky then you will have only a electrical failure. Worst that can happen is a electrical fire.
     
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  12. Hairy W Bush

    Hairy W Bush Member

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    ok I happen to have a brand new in box relay lying around so let me know if this is ok for this. it's an optronics a-715a 40 amp relay. it's a 4 terminal including power source and ground. so if I HAVE to go this route I have it.
    I was also thinking about greenmonster's idea, but a little more. I was thinking about removing the stock size green wire in there, and repinning the switch with a 10g. is this possible?
    also i am getting a new ignition switch. the readings are inconsistent and my power probe 3 making fast beeps when i test the line.
     
  13. Krazy Comet

    Krazy Comet Tom

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    LOL I doin't kno nuthin 'bout no power probe... I've been fixin this stuff for almost 50 years with a analog meter and test light... Ether there is 12v or not, either the test light burns at normal brightness or it doesn't, all in knowing the tools...

    Assuming you have a wiring diagram for relay, connect ground and and the reg/green to it's coil(should be 85 & 86), if relay clicks with ign on you're golden... Terminal #30 connects to power from battery #87 is is the 12v supply... Simple... That's exactly how mine is wired, been fine for almost two years...

    You can wire from relay with whatever gauge wire you want to use to feed dist...

    Note once the red/green wire is connected as I stated it CANNOT be used to supply anything else, at least not if you don't jump out the resistance wire in dash harness...
     

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