I just bought a tachometer from JCWhitney. It is a universal fit type thing with crappy instructions. It says "Make connection to the negative coil terminal to which is attached the small wire leading to the distributor." They don't mean the high voltage wire going from the coil to the distributor do they? It must be one of the wires going to the wiring harness, if so which one? This is a '92 f-150 with the I6 engine.

-Jon

 

I'm not very familiar with the I-6 engine but I hope this helps. I had the same question when I installed my tach. On my coil there is a plug in that connects to the coil. Do not connect the wire to the high voltage coil wire that goes to the distributor (you wont like what happens)

If your coil does not have the plug in it should have either 2 or 3 wires that are part of the harness.

Get a circuit testor. The thing that has an allgator clip on a lead and a light bulb in the handle.

Connect the clip to a good ground. Touch the other end into each of the wires. You may have to peel back some of the insulation so have some silicone to cover the bare spot after you are finished.

Start the engine and watch the bulb while you touch each of the wires. The negative wire will cause the light to flicker or pulse very fast. The others will either be a solid on light or nothing at all. The wire that flickers is the one you want.

I hope this helps,

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'96 F-150 302
Hedman Hedders, Catco Cat., Gibson Super Truck, K&N F.I.P.K.