Dash power running through Alternator gauge?

Electrical and Ignition

  1. briwill70

    briwill70 Well-Known Member

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    I recently pulled the gauges out of my 65 Dart to clean and paint the bezel. I thought the car had never been messed with but there was some modern, large gauge wires going to the Alternator gauge. One was hot coming from the wire bulkhead in the firewall and the other side went to what appears to be a cluster of wires behind the spedo. This looked questionable so I disconnected them from the gauge and sat them aside. Put the dash back together and now nothing works. No headlights, no ignition, no anything. Does all of the power run through that gauge? Doesn't seem right to me.
     
  2. TrailBeast

    TrailBeast AKA Mopars4us on Youtube

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    Ever hear of the MAD wiring bypass for the charging system?
    Sounds like what you are seeing, and that big red wire is what supplies everything with power.
    If you still have an amp gauge it connects to the back of that.

    Read up on it here.
    Catalog
     
  3. Michael Brisebois

    Michael Brisebois FABO Gold Member FABO Gold Member

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    What you'll need to do is connect the red and black together, bolt them and electrical tape the whole mess.

    The AMP gauge will be by-passed. I've heard that the AMP gauges can catch fire, if too much current goes through.....but I've never seen it. I'm still running the OEM
     
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    • jbc426

      jbc426 Well-Known Member

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      This....and then trace the two thick wires back to the bulkhead connector, unplug and clean the contacts there. I like to trim those disposable finger nail files to scuff the male side and a stainless steel toothbrush looking brush to clean the female side. Make sure the female side fits tightly on the male spade. I also cover the connections in dielectric grease. I have used scouring powder mixed with a bit of water to help clean the female spades with the small wire brush, and then rinse well. Check all of your wiring for damage and address any you find.

      You can also run a heavy cable from the output lug of your alternator to the positive post on your battery or starter relay lug(as long as you have a similar gauge cable from the starter relay stud to the positive battery terminal.)

      Make sure you fuse or add a fusible link to that cable with the appropriate size fusing. Car audio fuses can come in handy here if you can't find large enough rated fusible link wire.
       
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      • Mattax

        Mattax Just the facts, ma'am FABO Gold Member

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        Wish you guys would stop believing those sweeping generalizations.

        You just disconnected the battery power feed.
        The ammeter is in the battery feed/charge line. It shows whether the battery is charging or disharging, or neither.
        The '65 is a relatively good design and the fact the wires looked like new further suggests its in good condition.
        Put it back the way you found it. Make sure the battery and alternator wires do not contact any metal housings. (ground)
         
        Last edited: Apr 24, 2020
      • Mattax

        Mattax Just the facts, ma'am FABO Gold Member

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        Basic power circuit is like this.
        Cars have two power sources; the battery, and the alternator.
        Fusible link was added either '64 or '65.
        All of the wires connected to the battery are always 'hot' up to the switches.
        upload_2020-4-24_12-33-54.png

        Ammeters were used on all better instrumented vehicles.
        upload_2020-4-24_12-38-52.png

        ?u=https%3A%2F%2Fi.pinimg.com%2Foriginals%2F2f%2Fe7%2F8e%2F2fe78ec217a9714b0a696eab5b5b1288.jpg

        They were also a standard item for under dash gage sets (probably because many plain jane GM products had no instrumentation to speak of)
        upload_2020-4-24_12-50-18.png

        The important thing is to understand what its showing.
        From Chrysler's master tech 1960

        upload_2020-4-24_12-51-3.png

        Anything close to either extreme is a problem. (Your car's ammeter is calibrated to be 40 to 40 amps) If it stays at or over 40, its a big problem. Shut down.
        The fusible link will usually protect from the worst situations by melting.
        And if it stays pegged, disconnect battery.
         
        Last edited: Apr 24, 2020
      • 67Dart273

        67Dart273 FABO Gold Member FABO Gold Member

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        ................And one other thing. This wiring might be OEM, it might be a MAD bypass, or it might be the factory "fleet taxi police" wiring used with 65A alternator. Briwill, is there only two wires? A cluster? We need a photo............................
         
      • 67Dart273

        67Dart273 FABO Gold Member FABO Gold Member

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        u-https-3a-2f-2fi-pinimg-com-2foriginals-2f2f-2fe7-2f8e-2f2fe78ec217a9714b0a696eab5b5b1288-jpg.jpg

        On a side note, "it might be" that 'Vette cluster you pictured is a shunt ammeter and not the "full current" type such as used in Mopar A bodies............

        "In theory" a remote shunt ammeter is superior insofar as wiring problems and the infamous bulkhead connector. But many of them as applied practically are a POS. Many are so "numb" that when you turn on the headlights at rest you have a hard time without intently staring at the needle, to see if it really moved at all. I actually extended a wire in the harness---to intentionally cause more drop "in the shunt" and cause the meter to have more sensitivity. I did this "back in the day" for a couple of friend's of mine Fords. This was long before Al Gore "invented the internet"
         
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        • Mattax

          Mattax Just the facts, ma'am FABO Gold Member

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          Could be. A friend had one in the shop last year but he didn't get to work on it. Now I'm curious...
           
        • Mattax

          Mattax Just the facts, ma'am FABO Gold Member

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          That's a '63 C2 and it is remote shunted. Good call.
          Who was it that posted something about sweeping generalizations?
          whistling.gif
           
        • briwill70

          briwill70 Well-Known Member

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          Definitely is not a fleet wiring situation. 2 door, 270 grandma car. Amp gauge wires are newish and upon closer inspection there appears to be some melted wires under the dash close to the firewall bulk connector. (probably the reason for the fix.) Everything was working before I disconnected so I'm inclined to just reconnect for now.
           
        • Mattax

          Mattax Just the facts, ma'am FABO Gold Member

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          Get a s'65 Dodge or Plymouth shop manual if you don't already have.
          In the back of the electrical section there is a complete wiring diagram.
          Use that to identify which wires show damage by color, size and position in the connector.
          Then you'll have an idea of what to keep an eye out for problemwise.
          Main headlight circuit is a common one.
          Ignition circuit is also the alternator's control - and if that's damaged can mess up the voltage regulation.
          The ammeter will only indirectly indicate voltage regulation problem. If it is charging high or showing charge for long periods, or following the engine speed - then look into this possibility,
           
        • pt70

          pt70 Well-Known Member

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          Why do you have to express your political views on others? We know you believe the Fake News and choose to repeat it. Go to 'snopes .com' and read the explanation of how this false 'statement' got started. You'll be more knowledgeable and feel better about yourself.

          Don't drink the Lysol.
           
        • 67Dart273

          67Dart273 FABO Gold Member FABO Gold Member

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          Because its a joke, as big a joke as Al Gore is a joke. Al Gore is a turd, and a liar, dressed up in respectability, the same clothes that "buy a shotgun" Biden wears, and the same rumpled mess of rags that communist BerningMan Sanders tries to wear. I haven't drunk any lysol recently
           
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