Ammeter pegged...

Electrical and Ignition

  1. BillGrissom

    BillGrissom Well-Known Member

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    You lost me at "I'm a mechanical engineer, but can't read a wiring diagram". Are you talking university-educated from an ABET school? (not U of Phoenix). In my BSME studies I learned op amp circuits, motors, control systems, even analog computers (long ago). Then lasers and such in grad schools. Anyway, great info here, so all it takes is the ability to read and process info (most people lack) and there are youtube's to teach basics. Some here try to trouble-shoot w/o a multimeter, even though you tell them "free at Harbor Freight". The main issue is lack of initiative for those that fail. For sure fix your over-charging problem before the dash cluster melts and the battery generates hydrogen (can explode).
     
  2. toolmanmike

    toolmanmike FABO Staff Staff Member FABO Gold Member

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    They can and they will. I had a poor ground on my 66 Dart. It boiled the battery in a short order, blew out light bulbs and made a mess of the paint on the drivers side of the engine and under the hood. I sent my valve covers off to Leanna and she had to blast the drivers cover 2 or 3 times to get the powdercoat to stick. :BangHead::BangHead:
     
  3. 67Dart273

    67Dart273 Well-Known Member

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  4. 7milesout

    7milesout Well-Known Member

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    Reading wiring diagrams is not something I ever learned. And holding a degree of any sort does not make one smart. Since my first engineering job, I've not done electrical design. All mechanical. I'm glad you've experienced all you have.
     
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    • 67Dart273

      67Dart273 Well-Known Member

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      The thing is, you just about have to re-learn reading diagrams everytime you pick up something different. Ma, in 73, completely changed the way the 73 A body diagrams are displayed. Old ones are "line drawings."

      GM, Ford, have their differences, and all the "newer" stuff (Dodge Rams / Dakotas, etc) are different yet again. About all you can do is "dig in" and start looking

      I used to work in HVAC/R service. Those diagrams were MUCH different than the electronics/ communications/ RADAR stuff I'd worked with earlier. And, Lennox/ Carrier/ Coleman are all quite different from each other.
       
    • 7milesout

      7milesout Well-Known Member

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      Guys,

      I hate to be dragging this out. But I have teenage sons, that have lots of sports going on. And 2 parents both in chemotherapy. So, I don't have much time for El Scampo these days. I work on him when I can.

      Quick question. I mentioned about some melting of the alternator plastic terminal protector. Should I try finding another terminal protector? Or just butt-crimp and solder on a new eyelet, run the nut down on the eyelet, be done with it and let it go without a terminal protector?
       
    • Mattax

      Mattax Just the facts, ma'am FABO Gold Member

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      I would not butt connect wires unless its too short.
      First clip off ring terminal. Then the wire should slide. You could reuse the protector, get a new one, or go naked. That's up to you.
      More important is the condition of the wire - which you will see after you clip the connector.
      Also check the output stud. Is it loose? Is there continuity to ground?

      IMO the best repair of the wire will be a crimped on open barrel ring terminal of the proper size. The crimp and wire then inuslated with fuel and oil resistant shrink tubing. I still solder some things but given a choice here, that's what I'd do.
       
    • 7milesout

      7milesout Well-Known Member

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      Thanks Mattax - And yes, I said butt-crimp. But I meant to just crimp on an eyelet. I did some searches on Amazon. I think I'll get a protector. $6 or $7, should be a no brainer. And I believe I read that wire was a 10 awg. I'll get all the right stuff. I'll make sure the output stud is tight.
       
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      • Mattax

        Mattax Just the facts, ma'am FABO Gold Member

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        '73 FSM shows 12 AWG for standard alternators but '72 could have been different.

        The type of crimp I'm talking about has one portion to squeeze the wire strands and a second set of wings to hold the insulation and helps reduce stress and strains. I don't know where this photo originally came from but its a illustration.

        crimp-a-ring-terminal.jpg

        You'll need an open barrel crimper anyway to replace the other bad wires and tbeir terminals.
         
      • 7milesout

        7milesout Well-Known Member

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        Mattax and All -

        I got so much done this weekend. Got my son's CR 85R running again (had a blown headgasket and a crankcase full of coolant). Anywho. I procured a new VR because they're only about $30. I got it last week and brought it in to work and ground the paint off a mounting hole. Late last week I installed the VR and installed a ground wire under the bolt on the ground off metal (no paint) hole. I found a bolt that served as a good ground (confirmed it with my multi-meter). Installed the ground wire and double checked the terminals of the ground wire on both ends. Good continuity to the battery ground. So that was good to go.

        I couldn't find a reasonable boot for the alternator terminal so for now I just installed it with no boot. But I found a 10-12 awg eyelet terminal with a built on shrink tube and crimped it on. It looks just like the terminal in the post above, and yes, the wire is 12 awg, not 10 awg (you were right).

        Hooked it all back up after tightening the alternator stud nut. I fired up El Scampo. The ammeter went a little toward the + side immediately after firing, and slowly came down as the engine warmed and as the rpm came down as I backed off the choke. That seemed normal, and then it went perfectly centered when the choke was fully off. I let it idle for a while and watched and it never pegged out. And the AFR gauge worked correctly the whole time. The AFR gauge is a tattle tale as it freaks out when the ammeter pegs (the AFR gauge is bigger brighter than the ammeter so it serves as my indicator). This idle check was on Friday.

        Saturday we were at a bmx race all day. Sunday, worked on the CR 85R a while, sold my 450X, and then finished the CR 85R. Sunday evening my parents came to the Cancer center in Newnan (about 15 miles from me), and I decided to drive El Scampo and watch the ammeter, to meet them in Newnan for supper.

        I did and it never pegged out and stayed nominal the whole time (about 30 miles worth). I'll keep monitoring this, but it seems I may have this resolved.

        On a different note, I raised the floats (while it's been out of commission) from the suggested Edelbrock instructed float height. I raised the floats by 1/8th inch. It ran fine, but it has moved richer across the board. I didn't think a deeper puddle would affect the AFR, but had considered the possibility. I did this in an attempt to prevent the carb from running out of fuel at the drag strip. But I'll have to retune it because with a warm engine and at WOT it was running about 10.9:1, versus 12.2:1. And 12.2 gives it max power at WOT.

        Thanks for ALL THE SUPPORT!


        7milesout
         
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        • DemonK9

          DemonK9 Well-Known Member

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          ....if the issue arises again, you may want to check/replace the actual PLUG for the VR. I had the connections go bad/break inside the rubber of the plug once...and all seems normal, from the outside.
          It may have temporarily "fixed" itself since you have been handling the plug (bad connection inside plug making temporary contact until wiggling lose again)
          Seems like you have it fixed, but food for thought at something to look at, if it suddenly arises again.
           
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