1 Wire Alt Jumper Wires Issue

Discussion in 'Sparky's corner' started by blyons79, Oct 14, 2020.

  1. blyons79

    blyons79 Well-Known Member

    So I’m not sure what I did...but I have a problem. I converted my alternator to a 1 wire internally regulated u it a few years ago. Also switched to FITech and MSD dizzy and control box. While I was installing the MSD I figured I’d clean up the engine bay and get rid of any unused wiring. After cutting the wiring harness open I found what I thought were a bunch of unused wires. Now as you can imagine I have problems

    My battery isn’t charging but I think the alt is just bad...pulling it to get it tested tomorrow. My main concern is now when I turn my key back to listen to the stereo my fuel pump turns on and my FITech is clicking (squirting fuel down the intake). I suspect the issue is that I cut out the jumper wires where the old external regulator was. After following the wires it seemed to me they weren’t leading anywhere anyway.

    3F8A84A6-431A-4613-A5D6-B75DA9B2AA63.jpeg

    The red wire was jumping to the white, which wasn’t used and the brown wire was jumping to the blue which wasn’t used either. What am I missing? Pretty frustrating. Tired of looking at wiring diagrams....still makes no sense to me.
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The white and blue wires previously went to the old externally regulated alternator. The one wire alternator is probably a 10 or 12SI internally regulated alternator. The brown wire in the regulator harness is typically joined with the blue wire. The blue wire is hooked to the the SI pigtail white wire, and the red pigtail wire goes to the charging post along with the original charging wire. That's so the alternator light works in the dash.
    AlternatorIRPT.jpg


    The red wire at the external regulator connector needs to be cut and taped off. The white wire is eliminated.
     
    blyons79 likes this.
  3. blyons79

    blyons79 Well-Known Member

    I cut the brown wire at the harness on the firewall, leaving enough lead to tap. So I can just tap the brown wire and run it to the white pig tail wire, right?

    I guess I got confused by the “1 wire” name. Didn’t think anything else was necessary.

    I guess it’s safe to assume that none of this has anything to do with my fuel pump and throttle body issue. I have the MSD control box 12 volt wire and the throttle body 12 volt wire tied together at the 12 volt source that used to feed my ignition coil (from the wiring harness at the firewall). Do I need to separate them?
     
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yes.

    You can run them either way, but I believe it is better to run it with the pigtail.

    I would probably want to separate them. Looking at your picture, the fat red wire in the regulator plug, the other end of that tees into the alternator charging wire. Are you sure you taped that off. That would be a direct short if it touched a ground.
     
  5. blyons79

    blyons79 Well-Known Member

    Yeah that regulator plug is completely removed. I cut the wiring harness open and removed all unused wires and re-taped. Goal of the wiring is to be as simple as possible. Only fat red wires left in the harness go from the harness plug straight to the starter. I ran a new separate 8 gauge wire IIRC from the starter to the alternator. I cut the original alternator feed and and regulator feed at the junction in the harness.
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    OK, then you should be OK. At worse, you might have fried the internal regulator. They are cheap and pretty easy to change. There are youtube videos. The hardest part is loading the brushes back in.
     
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  7. blyons79

    blyons79 Well-Known Member

    What would be a good 12 volt source other than my old coil wire?
     
  8. blyons79

    blyons79 Well-Known Member

    Tap into the fat red wire the alt and regulator were tapped into?
     
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I would look into an auxiliary fuse block. Painless wiring sells different ones. That's the right way.
     
    blyons79 likes this.
  10. blyons79

    blyons79 Well-Known Member

    Thanks, Larry. Take care man.
     

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