This is exactly the thread I needed! I have one question though... here is where I sit, I have three wires to work with:

I have the one wire connected to the HEI distributor "tach" point.

I have a good ground (tested it with my multimeter)

I have the wire that is my equivalent to your "gray" wire hooked up to the window wiper motor power.

My tach lights come on, but the tach does not work.

Where is or what is the power/ignition wire rsclassics used?

I am good at tracing down wires... and apt at reading an electrical diagram, but I am a bit short on some of the knowledge as far as what is what...


Thanks!

(for those that have seen my other posts, I did get my brakes squared away, and the exhaust is going to cost me ... needs a lot of work... I figured this would be a cheep easy fix I could do myself... also clean up some wires!)