QUOTE(Geezer914 @ Jun 4 2011, 06:50 PM)
That's all the wires in that harness. The single black wire should be the tach wire. But like I said it's hot with the key on. How can I check to be shure its the tach wire?
Disconnect the 12 pin connector at the rear of the relay board; disconnect all wires from the coil; then, do a continuity test from pin 5 ( not seven) on the 12 pin connector to each of your suspected tach wires.
*** Corrections: Pin 5 is Tach