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  1. wedg2go

    wedg2go Well-Known Member

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    Factory production rally instrument cluster.

    Question - Can the amp gauge be wired in to a switched wire off the cluster (neg ground to frame) to work?

    or

    Will I need to wire from the alternator to gauge to battery?

    Seems the new wiring kit, the previous owner purchased, omitted the amp gauge (Or I'm missing something and over thinking this). So while it looked official, it never worked since my purchase.

    FYI - Factory tach works great, with MSD iginition, after updating electronics and after finding out the wiring was backwards. *heavy sigh* Second electrical something I found installed backwards on this ride. Waiting for the day smoke rolls out from under the dash. <<<J/k'g...I hope.

    Which leads me to the next question

    Second question - Can someone tell me which side, on the amp gauge, is positive and negative (just so I know for sure)?

    Thanks!!!
     
  2. 704406

    704406 Well-Known Member

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    To answer your second question first, the back of the gauge cluster is clearly marked with the wire colors, the amp gauge location has one side marked RED cast into the housing. The wires for the gauge are usually black and red.
    The factory wiring has a wire from the alternator thru the bulkhead to the amp gauge, from the other side of the gauge thru the bulkhead to the battery. If this was not a complete circuit obviously no charging will take place, unless a bulkhead wiring bypass was installed.
    I'm not sure why you would want a switch to ground in there somewhere
     
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  3. rklein71

    rklein71 Well-Known Member

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    Both sides are positive.
     
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  4. wedg2go

    wedg2go Well-Known Member

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    Didn't intend to indicate switch to ground. Meant to indicate from ignition switch to a positive charged wire in back of the instrument cluster.

    However, I can see now that won't work. Given that and the info you are telling me, I will need to place another run from the bulkhead to gauge (Hoping the wire is there from the alternator to the bulkhead). That's what I needed to know. I was doing my best to avoid adding another run, but Oh well.

    Appreciate it very much! Thank you.
     
  5. aussiemark

    aussiemark Well-Known Member

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    As rklein71 said the wire for the gauge is the one + wire with the gauge in the middle but I would just bypass the gauge who needs it or even looks at it anyway? You will know if you are having battery or charging system issues long before the amp gauge shows anything and if it burns the car to the ground you'll have bigger problems then a discharged battery or dead alternator.
     
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  6. wedg2go

    wedg2go Well-Known Member

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    I can't begin to tell you how many times I have read, "Bypass the gauge" on the net. Seems there are more than a few that will agree with you on this issue aussiemark. As far as who "even looks at it?" I did at first, but thought the charging system recovered the needed charge since everything was new including the battery. Imagine my surprise when I found the wire cut from the gauge when I removed the instrument panel.

    So here is my thought - Having an amp gauge did once save me from having a continuing issue with my other show car. So did listening to how it started when it was going though this issue (sluggish). Simply fix - new electronic regulator - and I was off and running again knowing the charging system was working via gauge. Better choice to be aware of potential problems before hand than being stranded in the Arizona desert when it hits triple digits.

    Then again, I can't seem to disagree with "even looks at it," since it is more than a quick glance after starting and that's it...For me. When I am out cruising, I watch first and foremost the temp gauge, tach and then the oil (Speedometer? What is a speedometer?). Is it worth the potential risk for fire? I don't know, but I'll can say I want to remove this instrument panel only once and no more. I hate hanging upside down under the dash connecting and disconnecting things.

    A ton of thought will be going into this today, but I really appreciate your view towards this issue aussiemark. Thanks!
     
  7. 340challconvert

    340challconvert Well-Known Member

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    These have been posted before from MAD;

    upload_2019-7-15_11-14-59.png
    The original AMP gauge system served as the main power distribution system. This circuit is the power source for the entire electrical system. (see diagram A)

    2nd pic show how to by pass the gauge
    upload_2019-7-15_11-19-30.png
     
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  8. moparlee

    moparlee Well-Known Member

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    My opinion is that if your car is basically stock without high power users like electric fans and stereos, keep the ammeter. Make sure ALL of your electrical connections are clean and tight and use dielectric grease on them.
     
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  9. wedg2go

    wedg2go Well-Known Member

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    Well, based on what the previous owner did - by passed the gauge via diagram posted above - I am going to leave it that way for now. I hate driving without knowing, but there is too much to do and very little time to do it for my situations. I'll leave some lengths of wiring off of it if I change my mind on some cold winter day.

    Thanks everyone!
     
  10. 340challconvert

    340challconvert Well-Known Member

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    One modification I found to be really "slick', changing out the stock amp gauge for a volt gauge. A sunpro gauge CP7985, modified is swapped out for the amp gauge with some modifications.
    Several people have done variations on this conversion.
    Check out this link from another enthusiast forum:
    (thanks to cudalbs and chal340 for the pics)

    Dino2 (1).gif
    Voltage gauge for Cuda rallye dash in Interior

    ;topic=685.png
     
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  11. moparleo

    moparleo Well-Known Member

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    :thumbsup: I highly recommend the conversion. The auto manufacturers have not used Ammeters for over 40 years for good reason. Voltage output is a better gauge for info than just Amps. As far as wanting accurate info on your cars functions, would you prefer idiot lights that light up when it is too late :BangHead: or accurate gauges that will actually tell/warn you that something is not right ??? :thankyou: Go with gauges.
     
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  12. wedg2go

    wedg2go Well-Known Member

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    I gotta say, that is one slick setup over in the other place.

    However, what you're showing in the photo is sweet. More my style! Where can I find the goods to fabricate that (Needle, and face match)?
     
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  13. 340challconvert

    340challconvert Well-Known Member

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    Sunpro CP7985 voltmeter is available on e bay at the best price, around $12.98 w free shipping (avoid ordering it from Amazon, vendors charge a higher price + shipping costs)
    The process seems to involve taking apart the old Amp meter and using the face plate and painting the needle to match. One of the conversions, the old needle was glued over the new volt gauge needle. Instrumental Specialties I believe sells a converted gauge and or a converted face plate.
    Definitely is a cool "factory look" while eliminating potential short/fire damage.
    Dino2 (1).gif
     
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