[azfordman]

I would like to test the tach before I send it off for repair/replacement to verify if the problem is the tach or wiring on the car. On the back of the unit there is a cluster of three spade connectors, +VE, -VE, and Trigger, there is also a 4th spade connector attached to the housing itself, another ground??? If I rig it up in the engine bay to test it how should I do it? The power + and - seem pretty straight forward, but where should I get the signal from? It is a stock ford pointless ignition system. Do I get signal directly off of the coil (if so, which side) or out of the ignition box? Thanks!