EFI help needed, Wiring questions.

Electrical and Ignition

  1. Kent mosby

    Kent mosby FABO Gold Member FABO Gold Member

    Messages:
    739
    Likes Received:
    678
    Joined:
    Aug 24, 2018
    Location:
    Idaho
    Local Time:
    1:23 AM
    I am converting my 73 scamp, 512RB to super sniper EFI. I have a new wiring harness that was for a small block. The Sniper EFI also has Hyperspark coil, Hyperspark distributor, and Hyperspark ignition. The alternator has a built in voltage regulator.

    Since I will not be using the original ignition components, How do I handle the wiring for the voltage regulator, the ballast resistor and the ignition module? as well as the others seen below?

    The oil light I will need and I will also run a gauge. The distributor and coil wires I will not need, do I cut then and cap them off? OR what??

    Also, What is that black wire with the rubber fitting used for/. I searched the FSM to no avail. It runs up by the battery and the rubber fitting is like the one for a temp sensor but that is pink or violet and already in place.

    Finally, I read earlier about there not being a wire that is hot on both cranking and running, and that we could combine 2 from the ballast resistor and get that. If so which ones? If not, what did I not understand?

    Thanks for any help and wisdom.
    IMG_0871 (1).jpg IMG_0870 (1).jpg IMG_0869 (1).jpg
     
  2. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

    Messages:
    49,693
    Likes Received:
    18008
    Joined:
    Oct 14, 2010
    Location:
    Idaho
    Local Time:
    1:23 AM
    YOU NEED to run over to MyMopar and download a free factory shop manual, as well as the aftermarket wiring diagrams. Some of those manuals, as well as the 73, came from the guys right here


    The single black: I would suggest you get an ohmeter and check it against the bulkhead connector (with harness unhooked from the firewall) and see what pins it "hits." It might be the brake switch warning down by the steering box

    The ignition plugs you can safe off or unwrap the (yeah I know, new) harness and snake them out of there, except for part of the ones that connect to the ballast

    You will want to use the same as the coil+ wire as your ignition feed. And you will want to jumper that to the "run" power at the ballast, and CHECK that it is hot in start

    HERE is how Mopar igntion switches work:

    There is only ONE switched ignition "run" power out under the hood and THAT IS UNFUSED. that is the dark blue IGN1 "run" circuit that goes to the ballast, and at some point, branches off to feed the VR, the alternator field, and some smog doo-dads if equipped, and electric choke, if equipped.

    BUT THIS RUN POWER!!!! goes DEAD during "start" (cranking). The ONLY source if ignition power during cranking is supplied by the brown coil bypass "IGN2" which comes from the ignition switch on a dedicated contact and feeds the coil+ side of the ballast resistor.

    So for EFI and other ignition systems which DO NOT use a ballast resistor, you must jumper the ballast resistor terminals together, so that IGN1 is hot in run, and IGN2 is hot in "start" and they both then connect to what "was" the coil + wire

    If ALL you cut out of the harness is the wires that go to the old electronic ignition connector you should be OK. This includes one of the wires from one of the paired white ballast connectors, the 5 wire ECU connector, and the 2 wire distributor connector.

    The other wire in the paired white connector goes to the coil ring terminal. Leave that intact, pull the male end out of the connector and tape it into the harness

    So what you should have disconnected is

    The 5 wire ECU connector, with wires unwrapped, going to the 2 wire dist. connector
    1 wire going to the other wire out of the paired white ballast connector
    1 wire that went to "ignition run" which you cut from the "run" group going to the ballast
    1 wire going to a ring terminal which would have gone to coil NEG

    Everythink else remains in place and should leave the power (IGN) terminal of the VR connector powered. If you want to reduce the footprint of the remaining white ballast connector, pull the terminals out of the connector shell, and tape them up and tape them into the harness. This is the end that should have those two terminals of that one paired connector should be jumpered together.
     
    Last edited: Mar 29, 2020
    • Thanks! Thanks! x 1
    • Kent mosby

      Kent mosby FABO Gold Member FABO Gold Member

      Messages:
      739
      Likes Received:
      678
      Joined:
      Aug 24, 2018
      Location:
      Idaho
      Local Time:
      1:23 AM
      I am going to have to read and reread that a bit. I am not an idiot. I have a doctorate degree but this is not my specialty. With Covid-19, my office will be closing tomorrow and I will work through this, bit by bit.

      Thanks so much
       
    • 67Dart273

      67Dart273 FABO Gold Member FABO Gold Member

      Messages:
      49,693
      Likes Received:
      18008
      Joined:
      Oct 14, 2010
      Location:
      Idaho
      Local Time:
      1:23 AM
      It is actually fairly simple. The hard part is getting it "neat."

      The two white connectors originally connected to the ballast.

      1... One of those should have both terminals jumpered together. So the two terminals on one white shell are one big splice. Electrically you need to leave that all connected.

      2....The remaining white connector, one wire/ terminal went to the ECU and is no longer used. If you pull that out of there it leads off to the 5 wire ECU connector

      The second terminal goes one wire off to the coil + ring terminal, and the second wire is your brown IGN2 bypass circuit. That terminal, those two wires, get jumpered to the first, (1) above and the coil + ring terminal then becomes your switched ignition to key on the EFI and ignition

      Then, there is one wire coming from the ECU connector that goes splices into the circuit from (1). So you can snake that one out or tape it off and actually, if you leave some of it "in the harness" you can use it for the wire you need to jumper / splice over to (2)
       
      • Thanks! Thanks! x 1
      • MoparMike1974

        MoparMike1974 FABO Gold Member FABO Gold Member

        Messages:
        3,249
        Likes Received:
        2544
        Joined:
        Jun 16, 2017
        Location:
        Maryland
        Local Time:
        4:23 AM
        When I did my EFI I bought a new engine harness and integrated all of the efi wiring into it. At the same time I removed anything that was not needed.
         
        • Like Like x 1
        • matthon

          matthon Well-Known Member

          Messages:
          2,499
          Likes Received:
          681
          Joined:
          Aug 29, 2008
          Local Time:
          4:23 AM
          I bought two wire hubs, one red one black. Mounted the red one under the dash, and the black one next to the battery.

          They were essential in making clean connections for multiple wires.

          For example, I ran the ignition run and start to the positive hub, and hooked the voltmeter there as well.

          Before efi, when I installed my msd, I made a jumper wire and hollowed out the back of the ballast resistor. It looked stock and I didn't have to splice wires.

          When I converted to efi, I bought a 4Runner alternator, eliminating the external vr, and thought, I don't even need all these wires going out into the engine bay, splicing, dicing, etc.

          I bought the hubs, and integrated a Painless 7 fuse box into the existing harnesses. Mounted in the factory location, using new factory terminals, slid into the existing factory plastic connectors.

          The factory 'splice' in the dash harness was completely bypassed, not needed, not a single wire connected to the splice was used.
          I also have fused items that were not from the factory, iirc heater, headlight switch, etc.
           
          • Like Like x 1
          • mario03srt

            mario03srt FABO Gold Member FABO Gold Member

            Messages:
            677
            Likes Received:
            163
            Joined:
            Apr 12, 2015
            Location:
            Amelia Oh
            Local Time:
            4:23 AM
            Kent,

            The short of it is to cut the unneeded wiring away. The blue and brown wires on my Dart are combined to crank and maintain ignition. These come out of the distribution block. Be sure to use relays! I run a FiTech setup. If you have not done so see the MADD wiring diagram to be sure that you replace all the jakey small gage wiring especially the alternator and the main power going into the firewall to the ammeter. A tip that I can share is to ground the throttlebody to the block from one of the mani mounting studs for trouble free ;) operation. Remember grounds are you friend. Replace and add any or all that you can. How many amps is your alt? Be sure to have enough!

            FYI,
            Marion
             
            • Like Like x 1
            • tanis4457

              tanis4457 Well-Known Member

              Messages:
              360
              Likes Received:
              101
              Joined:
              Apr 22, 2015
              Location:
              Mountlake Terrace, WA
              Local Time:
              1:23 AM
              I've installed two Holley sniper kits (using the coil module only), the best plan of attack here is to verify which wires provide 12volt at cranking, all the time or in the run position only with a voltmeter. Then you can figure which wires you want to run to the Holley kit for the switched voltage and the on all the time 12 volt. Your probably going to end up with some wires you no longer need.
               
              • Thanks! Thanks! x 1
              • 67Dart273

                67Dart273 FABO Gold Member FABO Gold Member

                Messages:
                49,693
                Likes Received:
                18008
                Joined:
                Oct 14, 2010
                Location:
                Idaho
                Local Time:
                1:23 AM
                CAREFUL it is not a hit miss "which wires verify".

                THERE ARE ONLY 3 WIRES that come from the ignition switch and into the engine bay which are involved here

                1 There is ONLY ONE "run" wire, normally dark blue, and "goes cold" during start

                2...IGN2 the brown bypass circuit, hot ONLY in cranking. This is SEPARATE from the "start" wire to the start relay

                The IGN1 and IGN2 are to be jumpered together with a non-stock ignition, which does NOT use a ballast resistor

                3.. The normall yellow "crank" AND IT IS NOT TO BE USED FOR any other purpose. WHY?? Because it will cause a backfeed condition in park or neutral, and MAY even cause the starter to stay engaged in park or neutral this wire goes to the starter relay

                The "unless" is that you can use a second relay off this wire, or "steering diodes" to isolate other circuits. This might be say, if an alternative ignition switch (GM or aftermarket) which does not have the IGN2 circuit
                 
                • Like Like x 1
                • 67Dart273

                  67Dart273 FABO Gold Member FABO Gold Member

                  Messages:
                  49,693
                  Likes Received:
                  18008
                  Joined:
                  Oct 14, 2010
                  Location:
                  Idaho
                  Local Time:
                  1:23 AM
                  Relays are good even on stock, non EFI cars. If you "cut" (electrically) the blue "run" wire as it comes into the engine bay, use the firewall end to fire a relay, feed the other end from the load contacts, and pull power off say, the starter relay stud through a fuse/ breaker, this will normally cure the VR over voltage problems caused by harness voltage drop
                   
                  • Like Like x 1
                  • tanis4457

                    tanis4457 Well-Known Member

                    Messages:
                    360
                    Likes Received:
                    101
                    Joined:
                    Apr 22, 2015
                    Location:
                    Mountlake Terrace, WA
                    Local Time:
                    1:23 AM
                    I agree, wire in a relay for both your switched and full time power needs for the Holley. On one car I used a smaller fuse block (6-8 position), with the voltage fed to it via a larger gauge wire which is controlled via a relay, for the both the switched/full time.

                    Here's a quick visio drawing a made for the poster's reference. I didn't match the colors for the switched or fulltime wires to your vehicle since I don't know what you have.
                    CarRelayWiring.png
                     
                    • Thanks! Thanks! x 1
                    • Kent mosby

                      Kent mosby FABO Gold Member FABO Gold Member

                      Messages:
                      739
                      Likes Received:
                      678
                      Joined:
                      Aug 24, 2018
                      Location:
                      Idaho
                      Local Time:
                      1:23 AM
                      If my alternator is internally regulated and has a sense wire that goes to a 12v source, (either the starter relay or a distribution block to battery +) wouldn't that eliminate any overcharging caused by harness voltage drop? Also, when I jumper the dark blue and Brown together, the ecu , the ballast resistor wires have nowhere to go. So can I get rid of them, the 5 wire connector, the VR connector and the white ballast connectors . None of them go back into the harness..and there is no VR, ecu or ballast resistors? Help. please @67Dart273

                      For now I will be skipping the relays. Soon, within weeks after getting it running, I will tackle the relays. I will bypass the Amp gauge for now and use a voltage gauge.
                       
                    • 67Dart273

                      67Dart273 FABO Gold Member FABO Gold Member

                      Messages:
                      49,693
                      Likes Received:
                      18008
                      Joined:
                      Oct 14, 2010
                      Location:
                      Idaho
                      Local Time:
                      1:23 AM
                      Not necessarily depends on where you connect the sense wire. The original VR power/ sense wire is essentially connected at the white ballast connector you had in your hand, the "run" wire. By that I mean spliced in there or somewhere near.
                       
                    • 67Dart273

                      67Dart273 FABO Gold Member FABO Gold Member

                      Messages:
                      49,693
                      Likes Received:
                      18008
                      Joined:
                      Oct 14, 2010
                      Location:
                      Idaho
                      Local Time:
                      1:23 AM
                      I thought I addressed this, read above again. The dark blue/ brown need indeed tied together and that splice is what feeds your EFI power "trigger." That was the reference to the old coil+ wire which "becomes" that wire lead.

                      And yes, reread posts above, you can unwrap and remove the ECU wiring and connectors

                      Essentially the dark blue "run" feeds several things depending on the year

                      Ignition run circuit feeds coil through ballast, and power to the ECU, and originally dropped power to the ECU through the second half of the ballast

                      Alternator field (light blue) VR power and sense--goes to the VR connector. (The green from the VR connector goes back to the alternator field, so it's a "dead" wire if not used)

                      If electric choke is used, feeds that

                      Some years, it feeds some smog doo dads.
                       
                    • MoparMike1974

                      MoparMike1974 FABO Gold Member FABO Gold Member

                      Messages:
                      3,249
                      Likes Received:
                      2544
                      Joined:
                      Jun 16, 2017
                      Location:
                      Maryland
                      Local Time:
                      4:23 AM
                      I agree, use the original switched hot wire to switch a relay. This takes almost all the load off the bulkhead connector. This is important when adding EFI since it will be powering much more than it was designed to.
                       
                    • Kent mosby

                      Kent mosby FABO Gold Member FABO Gold Member

                      Messages:
                      739
                      Likes Received:
                      678
                      Joined:
                      Aug 24, 2018
                      Location:
                      Idaho
                      Local Time:
                      1:23 AM
                      "Everything else remains in place and should leave the power (IGN) terminal of the VR connector powered. If you want to reduce the footprint of the remaining white ballast connector, pull the terminals out of the connector shell, and tape them up and tape them into the harness. This is the end that should have those two terminals of that one paired connector should be jumpered together."

                      This is the confusing part. Honestly, I have read your help 10 times. When I jumpered the blue and brown together, I have the rest of the harness with nothing that connects to them. No VR, ECU or ballast resistors. The picture is what I have left on the harness. All the other info made sense. I removed the distributor and other coil wires from the loom.

                      Since the green wire(not in this picture) goes to the alternator in the loom from the VR, I was going to use that as the sense wire back to the 12 V+ at a junction block. Good or bad

                      Again, thanks for your patience and wisdom
                      E8F18BFD-748C-4C77-B180-3617C0CF2FBC.jpeg
                       
                    • matthon

                      matthon Well-Known Member

                      Messages:
                      2,499
                      Likes Received:
                      681
                      Joined:
                      Aug 29, 2008
                      Local Time:
                      4:23 AM
                      Fyi: New Fuse Box Questions

                      I believe I made a change but nothing major. I did zip tie an inline fuse to the side of the fuse box for the tan/orange wires.

                      67 wiring diagram attached.

                      Found my updated, more detailed write up: Wiring harness

                      20180108_215235.jpg
                       
                      Last edited: Mar 30, 2020
                      • Thanks! Thanks! x 1
                      • 67Dart273

                        67Dart273 FABO Gold Member FABO Gold Member

                        Messages:
                        49,693
                        Likes Received:
                        18008
                        Joined:
                        Oct 14, 2010
                        Location:
                        Idaho
                        Local Time:
                        1:23 AM
                        OK, lol, but I don't see any of the VR wiring in your photo. You could have used say, the blue field wire "as is" for sense to the new VR as it splices into the harness. Actually "I'm not sure" just exactly where in the harness, but it HAS to splice into the blue "run." Otherwise, splice whatever you want into the splice there with the blue/ brown, as that is the "point" in the harness that is the "run" wire. The only thing the brown does, is to solve the problem of the "run" going cold during cranking.

                        So did you snake some more stuff out of there that is not pictured?

                        I don't care too much for your idea of the green wire, as it originally was not a power wire, although it will work.

                        The eyelet end wire you show there is the coil NEG and that indeed is not needed.
                         
                      • Kent mosby

                        Kent mosby FABO Gold Member FABO Gold Member

                        Messages:
                        739
                        Likes Received:
                        678
                        Joined:
                        Aug 24, 2018
                        Location:
                        Idaho
                        Local Time:
                        1:23 AM
                        I have not snaked anything else out yet, but I plan on removing the VR green and blue wires. The use of the green wire is simply that it has the correct connector and runs in the correct direction and along the harness that I would need for a sensing wire to the starter relay. Trying to keep it as neat as possible.
                        Thanks again.
                        Kent

                        BTW, one of these days we have to meet in real life. We are probably only 10-15 miles apart
                         
                      • 67Dart273

                        67Dart273 FABO Gold Member FABO Gold Member

                        Messages:
                        49,693
                        Likes Received:
                        18008
                        Joined:
                        Oct 14, 2010
                        Location:
                        Idaho
                        Local Time:
                        1:23 AM
                        LOL I'm 71, I hope I live that long. I work part time 3 days a week building power wheelchair components. I'm seriously considering telling them to "stick" it with the current events
                         
                      1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
                        By continuing to use this site, you are consenting to our use of cookies.