Mopar/GM HEI wiring diagram using a bosch relay

Mopar General Discussions

  1. rustytoolss

    rustytoolss Well-Known Member

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    When I updated my ignition system I used the GM 4 pin unit. I also used a Bosch relay. It has work great for several years :) until today :( . The car fires up while on the cranks side of the key switch...But dies once I let the key go into run . Kind of like a bad ballast resistor (which it no longer has).
    Does anyone have a mopar/GM HEI wiring diagram that includes using a bosch type relay. I've miss placed my diagram that I used when doing this conversion.
    Can someone move this to the correct location...think I put it in the wrong spot..thanks
     
  2. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    Because some relays don't have a diode, there are two ways you could connect the coil, and 2 ways you could connect the contacts. This combination results in at least 4 ways I can think of

    Plus there are variations in so called "Bosch" relays

    Here is one scenario

    wonderful-bosch-relay-12v-30a-wiring-diagram-along-with-wiring-diagram-for-a-12v-relay-500x500.jpg

    .............and......

    ch-relay-switch-diagram-google-search-electrical-with-regard-to-bosch-4-pin-relay-wiring-diagram.jpg

    Also you must jumper ign1 (run) and ign2 (coil bypass) together "Most years" the run wire is dark blue, the bypass is brown
     
  3. JoeSBP

    JoeSBP RLTW! FABO Gold Member

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    So you are using both IGN1 and IGN2 as a relay trigger?
     
  4. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    You must. IGN1 is hot ONLY in the "run" position of the key, no other position. This means there will be no ignition power during "start."

    During start, IGN2 is hot, (brown) a nd this originally went to the coil+ side of the ballast resistor
     
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    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

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      All,

      I used the stock Blu/Brn from the dist block combined to trigger the relay position 86 during both crank and ign power on with the key, 12v 10 gage from the battery to 30, position 87 to the HEI, position 85 to a new clean firewall ground location.

      FYI,
      Marion
       
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