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Thread: Tach Adapter 8920 - Stock '69 Ford Mustang Tachometer

  1. #1

    Default Tach Adapter 8920 - Stock '69 Ford Mustang Tachometer

    Hi. I've purchased the MSD 8920 tach adapter. Current Triggered: If the tachometer trigger wire was originally connected to the coil positive terminal, then the tachometer is Current Triggered.

    But if I connect 12 volt to the tach and then into the MSD 8920 Tach Adapter, is my Tach gonna fry? Or does the MSD 8920 Tach Adapter protect the tachometer and reduce the voltage to 9 volt? As the diagrams explain how to connect it. There's no more resistor wire in the car. I'm also using the MSD 6AL box. Regards, Rob

  2. #2


    The resistor was there to protect the points in the distributor, since normally on current triggered setups they're what supplied voltage to the coil & distributor. So there should be no need for the resistor or lowered voltage for the tach.

  3. #3


    Thanks. So the tachometer can handle 12 volts? If I used a coil that runs on 12 volt it would fry the tach. Running like the original setup. Regards, Rob

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