Switched Ignition Source

Discussion in 'Electrical Systems' started by Elliott Taylor, Jun 19, 2021.

  1. Elliott Taylor

    Elliott Taylor Member

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    Hey Guys,

    I have Sniper EFI installed on my 77 Camaro. I'm not sure how familiar you guys are with Sniper, but in order to make it function, you have to use a switched 12V source. Currently I am using a spade terminal on my fuse panel under the dash.

    I am about to install timing control for the Sniper, which will require 2 more switched ignition 12V sources.

    I'm not a wiring expert...Do you guys have any suggestions on what would be a good source on this cars factory harness?

    I don't see anything else on the fuse panel that I can use that isn't already being used.

    Thanks
     
  2. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    How many Amps does it draw?

    The wiper motor is a fused, switched ignition power source.

    You can also join all three wires together on one spade terminal to use the single port in the fuse block.
     
  3. Elliott Taylor

    Elliott Taylor Member

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    What if I combine all three with a relay? I haven't located the wiper motor source yet.. I'll look

    It's ok to combine all 3 on one terminal ?
     
  4. Elliott Taylor

    Elliott Taylor Member

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    I actually just realized something..Since I will be doing away with my HEI, I can just use the switched 12 V wire I have been using for it..?
     
  5. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    That should work.
    The HEI feed gets power in start and run positions of the ignition switch.
     
  6. Elliott Taylor

    Elliott Taylor Member

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    And cranking, right ? That’s the big one for this setup. I can check with a voltmeter, too
     
  7. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    Cranking is the "Start" position.
     
  8. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    That's what I'm using on my ProFlo 4 system.
     
  9. Jim Streib

    Jim Streib https://www.flickr.com/photos/[email protected]/albums

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    It's going to depend on where this was getting power from.

    I would look at how that wire is protected.

    If it is unprotected, but maybe going back to a fusible link supplying power to the ignition switch, maybe think about protecting that wire past where you are going to make connections to it to where if an overload or short were to occur then this would blow something like a fuse instead of trying to have it blow a fusible link off of the starter to where if that blew, the whole car would go dead and then be in a spot that would be hard to replace to get you back on the road.

    I know fusible links have their place but I'm not sold on them and would rather use a proper sized and designed fuse.

    Just make things safe, reliable, and easily serviceable.

    Jim
     
  10. kenny77

    kenny77 Veteran Member Lifetime Gold Member

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    This is what Relays are for. Run a fused 12V from the battery. Then the switched line to the relay from one of your fuse box ignition terminals that are being used
    Super safe that way and the best part is you don't have to worry about any other stuff that " might or might not" be hooked into that circuit that you're dicking around with and tapping into
     
    Zee and mrfleet12 like this.

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