You'll need a stomp starter switch for a 12 volt truck, 55 2nd. series or newer. It will have a small terminal for a wire going to the downstream side of the ballast resistor so the coil gets full battery voltage during cranking. Otherwise, the resistor drops the voltage down to 6 volts or so due to the starting load on the battery reducing the upstream voltage on the resistor. That's probably why you're seeing a weak spark while cranking. Try using a jumper wire directly from the battery cable on the starter switch to the + terminal of the coil and see if the spark looks better as you crank the engine.
Jerry

Last edited by Hotrod Lincoln; 01/28/2011 4:54 PM.
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