Help determining 2 wires

1968 -1970 Mopars

  1. pearljam724

    pearljam724 Well-Known Member

    Messages:
    756
    Likes Received:
    284
    Joined:
    Oct 14, 2018
    Location:
    Pennsylvania
    Local Time:
    11:22 PM
    69 Coronet - Anyone know what these 2 wires are for ? One is yellow, other dark green. Original air conditioning car, but not hooked up, They run along the fire wall and end behind the distributor. I don’t think they were attached to anything when I bought the car.

    5510AF80-6EA1-45AA-9CD6-38A847BC00FA.jpeg
     
  2. 1 Wild R/T

    1 Wild R/T Well-Known Member

    Messages:
    894
    Likes Received:
    1398
    Joined:
    Jul 9, 2019
    Location:
    California
    Local Time:
    11:22 PM
    The dark green looks like it is just a short wire that is bolted to the firewall? It appears to be a ground...

    Any chance the yellow is actually gray but looks yellow because of residue? If so it could be the oil pressure sender wire
     
  3. pearljam724

    pearljam724 Well-Known Member

    Messages:
    756
    Likes Received:
    284
    Joined:
    Oct 14, 2018
    Location:
    Pennsylvania
    Local Time:
    11:22 PM
    I think you’re definitely right about the yellow being oil pressure sender. It has aftermarket gauges. So that explains one. I’m pretty sure it’s yellow. But, it’s discolored and old. So it may have turned yellow perhaps.
    I wish I had a good colored schematic. The one in the manual stinks being it’s black and white. I have a convertible and for the life of me, I can’t get the rear courtesy lights to work. I’ve had the panels off, changed and fiddled around with bulb sockets. They are clean. To no avail. I wonder what the green wire is supposed to ground, as you say. Thank you, greatly
     
  4. moparedtn

    moparedtn FBBO Gold Member FBBO Gold Member

    Messages:
    5,073
    Likes Received:
    6778
    Joined:
    May 14, 2011
    Location:
    On the Ridge, TN
    Local Time:
    11:22 PM
    • Thanks! Thanks! x 1
    • Agree Agree x 1
    • 1 Wild R/T

      1 Wild R/T Well-Known Member

      Messages:
      894
      Likes Received:
      1398
      Joined:
      Jul 9, 2019
      Location:
      California
      Local Time:
      11:22 PM

      What bulbs are you using in the courtesy lights? They take an odd bulb with both terminals on the bottom, the brass base doesn't serve an electrical function at all.... May times someone puts a more conventional bulb in those sockets with acts as either an open or a dead short depending on how lucky you are...
       
    • pearljam724

      pearljam724 Well-Known Member

      Messages:
      756
      Likes Received:
      284
      Joined:
      Oct 14, 2018
      Location:
      Pennsylvania
      Local Time:
      11:22 PM
      I ll have to check bulb number. It matched end wise.
       
    • pearljam724

      pearljam724 Well-Known Member

      Messages:
      756
      Likes Received:
      284
      Joined:
      Oct 14, 2018
      Location:
      Pennsylvania
      Local Time:
      11:22 PM
      I thought it was alternator, must go to the original gauge. Those must be the two wires someone disconnected when installing aftermarket gauges. Now that I have a better speedometer and everything works on it. I can see if that gauge works too. I prefer aftermarket gauges. But, it’s nice to know what works and what doesn’t. Thank you, you guys are a good bunch on here
       
      Last edited: Sep 11, 2019
      • Thanks! Thanks! x 1
      • 1 Wild R/T

        1 Wild R/T Well-Known Member

        Messages:
        894
        Likes Received:
        1398
        Joined:
        Jul 9, 2019
        Location:
        California
        Local Time:
        11:22 PM
        If that green wire is bolted to the firewall like it looks like in your photo it has nothing to do with the alternator or gauges.....

        The only green wire that typically goes to the alternator is on a 70 or newer vehicle....
         
      • pearljam724

        pearljam724 Well-Known Member

        Messages:
        756
        Likes Received:
        284
        Joined:
        Oct 14, 2018
        Location:
        Pennsylvania
        Local Time:
        11:22 PM
        It’s not bolted to the firewall, both wires are bundled in with some other stuff on the firewall just hanging there loose. I pulled them out for a better pic. I think it is alternator. Explains exactly why those two are unconnected, aftermarket gauges. I’ll run a jumper wire in next few days to check it. I don’t think it was ever bolted to firewall. Someone hacked all of the wiring to alternator to hook up new gauges. But, I know. Eye hole connector makes that theory confusing. You may be right.
         
        Last edited: Sep 12, 2019
      • moparedtn

        moparedtn FBBO Gold Member FBBO Gold Member

        Messages:
        5,073
        Likes Received:
        6778
        Joined:
        May 14, 2011
        Location:
        On the Ridge, TN
        Local Time:
        11:22 PM
        I offered the link to the actual original wiring diagram to his specific car that shows otherwise.
        Of course, who knows what changes in the wiring have occurred over the last 50 years, but according to the diagram, there is indeed a green wire going to the alternator.
         
      • Richard Cranium

        Richard Cranium FBBO Gold Member FBBO Gold Member

        Messages:
        24,583
        Likes Received:
        53669
        Joined:
        Feb 20, 2012
        Local Time:
        10:22 PM
        These guys are experts with wires....


         
      • 71charger_fan

        71charger_fan Well-Known Member

        Messages:
        665
        Likes Received:
        1418
        Joined:
        Jul 19, 2008
        Location:
        Frederick, Maryland
        Local Time:
        10:22 PM
        [QUOTE="I wish I had a good colored schematic. The one in the manual stinks being it’s black and white. I have a convertible and for the life of me, I can’t get the rear courtesy lights to work. I’ve had the panels off, changed and fiddled around with bulb sockets. They are clean. To no avail. I wonder what the green wire is supposed to ground, as you say. Thank you, greatly[/QUOTE]
        I finally just bought a good set of colored pencils (they were only about $5 from Amazon) and went to work on my FSM when I was troubleshooting my wiring.
        phpO5eFo7PM.jpg
         
        • Like Like x 1
        • pearljam724

          pearljam724 Well-Known Member

          Messages:
          756
          Likes Received:
          284
          Joined:
          Oct 14, 2018
          Location:
          Pennsylvania
          Local Time:
          11:22 PM
          Good idea
           
          • Agree Agree x 1
          • 1 Wild R/T

            1 Wild R/T Well-Known Member

            Messages:
            894
            Likes Received:
            1398
            Joined:
            Jul 9, 2019
            Location:
            California
            Local Time:
            11:22 PM
            Sorry I didn’t see the link, you are 100% correct. In my experience that wire is generally dark blue.. Whatever I agree it’s actually probably the voltage regulator connection going to the alternator
             
          • pearljam724

            pearljam724 Well-Known Member

            Messages:
            756
            Likes Received:
            284
            Joined:
            Oct 14, 2018
            Location:
            Pennsylvania
            Local Time:
            11:22 PM
            Is the voltage regulator only needed when using the original gauge ? I ll have to take a look at how mine is wired. There’s a new one on the firewall, so this kind of adds to the confusion that it’s not hooked up. It’s definitely a alternator wire. Same exact dark green and gauge thickness.
             
          • 1 Wild R/T

            1 Wild R/T Well-Known Member

            Messages:
            894
            Likes Received:
            1398
            Joined:
            Jul 9, 2019
            Location:
            California
            Local Time:
            11:22 PM
            Do you have access to a basic meter? I would ohm the wire, check for continuity to the green wire at the alternator & wires at the voltage regulator...

            Take a picture of your regulator & post it
             
          • moparedtn

            moparedtn FBBO Gold Member FBBO Gold Member

            Messages:
            5,073
            Likes Received:
            6778
            Joined:
            May 14, 2011
            Location:
            On the Ridge, TN
            Local Time:
            11:22 PM
            The purpose of the voltage regulator has nothing to do with a gauge; it is a literal name - voltage regulator.
            It controls alternator output voltage.
             
          • pearljam724

            pearljam724 Well-Known Member

            Messages:
            756
            Likes Received:
            284
            Joined:
            Oct 14, 2018
            Location:
            Pennsylvania
            Local Time:
            11:22 PM
            Welp, we were all wrong and it almost cost me an engine rebuild and hearing in my left ear, lol !
            Trying to make this short as I can. I’ve done a ton of crap to this car in this past few weeks. Distributor leak fix, new timing chain, u-joints, rear end leak, intake gaskets, fixed a couple major leaks and other things.
            I had everything buttoned up and put back together. Cranked it, no fire. Cranked it 3 or 4 more times, no fire. I check for spark nothing. It was then I realized, that the green wire goes to the ballast resister and I forgot to put it on the coil. Praying, I hadn’t screwed up the timing gears when I installed them. Attach green wire, crank it for several seconds. Then the loudest backfire known to man. It literally sounded like a bomb went off in my left ear because I had the window down in my garage.
            Thinking no way in hell did my pistons survive that. I put a screwdriver in each plug hole to test for holes. To my surprise they seemed ok. But, the next test was to crank the motor again to see if I damaged anything. I was scared that it would happen again. I’m telling you guys, had the hood been closed, it would have blown off. I think I had the distributor 180 out too. After I timed it 10 degrees in advance, it fired up first crank and idled good as ever. I previously timed it at top dead center on exhaust stroke. It amazed me that a piston didn’t blow a hole. Unbelievable, loud. No kidding, my left ear hurt for 3 or 4 hours and still does a little. I’ve witnessed a lot of backfires in my life. Nothing like this one. It wasn’t a pop or a loud crack. It was a bomb sound. Major percussion.
             
            Last edited: Sep 14, 2019
            • Like Like x 1
            • Kern Dog

              Kern Dog FBBO Gold Member FBBO Gold Member

              Messages:
              12,803
              Likes Received:
              26284
              Joined:
              Apr 13, 2012
              Location:
              Granite Bay CA
              Local Time:
              8:22 PM
              That is some funny shit. The backfire was probably raw fuel igniting in the exhaust system.
              I knew this one guy years ago....The type of guy that was fun to hang out with but was always doing stupid shit. One time he rented a big U-Haul truck when he moved from Reno to Sacramento. He liked to floor the gas pedal and turn the ignition key OFF for a few seconds, then turn it back on. It made some obnoxiously L O U D backfires....THEN blew the muffler wide open. He coasted it into the rental lot and turned in the keys quickly...
               
            • pearljam724

              pearljam724 Well-Known Member

              Messages:
              756
              Likes Received:
              284
              Joined:
              Oct 14, 2018
              Location:
              Pennsylvania
              Local Time:
              11:22 PM
              That’s why I would never go into the renting business of any kind. Yep, that’s what happened to me. Raw fuel that was finally ignited when I eventually connected the green wire. No kidding, it’s been about 20 hrs and my left ear still hurts.
               
              Last edited: Sep 15, 2019
            1. This site uses cookies to help personalise 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.