Rallye dash voltage regulator

Electrical and Ignition

  1. 70Duster340

    70Duster340 Well-Known Member

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    I understand that the voltage regulator on the Rallye dash is located in the fuel gauge. I would like to replace it with a solid state (i.e., homemade) regulator. Can this be done, and if so, what would it take, parts-wise?

    Also, where is the darn thing?
     
  2. Dubob

    Dubob Well-Known Member

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    • RedFish

      RedFish Well-Known Member

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      You really don't need to open the fuel gauge to bend the little thingy ( unless you want to see if the fuel gauge side is also as toasted as the one RTE has pictured ).
      If you trust that fuel gauge side is in good working condition... Simply lift the gauge from the instrument housing to reveal a small piece of metal that provides chassis ground for the limiter. Place a layer or 2 of electric tape over this piece of metal to isolate this gauge from chassis ground just like any 2 post gauge is mounted.
      Next step. There's a blue with white tracer at 9 o'clock position of round harness connector. At ign' switch on it does nothing more than supply 12 volts to the OEM limiter, so... remove it from the connector and route it directly to the replacement solid state regulator wherever you choose to mount it.
      Next step... 5 volt output from solid state regulator can go to any one of 3 thermal gauge input studs. Simply use a ring terminal, toothed washer, and additional hex nut, similar to what you have at amp gauge studs, on top of the OEM stamped tin speedy nut.
      Final step is the most important. If a homemade regulator with the basic solid state 7805 package is used and it looses chassis ground, it can and will pass full voltage to the gauges at switch on. So no matter where you choose to mount the thing, ensure that it is chassis grounded at all times.
      The fact is, that simple 7805 regulator doesn't have any ground fault protection in it.
      RTE has that protection included in their units circuitry. I wont go into the other reasons their unit is worth the cost.
       
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      • 70Duster340

        70Duster340 Well-Known Member

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        Thanks so much, folks. This site is great! You all are very helpful!
         
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