The white tach wire comes from the instrument panel through the firewall to the engine. The tach gauge gets power from the pink wire that powers the other gauges.

 

Hey Don. Hope I’m getting this straight, new engine harness under dash ( that has the (( white. Tach/coil) wire with it is out in engine bay now. The white wire goes to - on coil.
Under dash on harness with other wires it’s plugged into its mating connection, what I can’t see or trace, is where does other end of wire go ? Looks like to new fuse panel I could be wrong,? ( like I said I can’t trace other end under there. With that in mind, do I just run a wire from remote tach to - post on coil aswell ?
Thanks. Hope this is clear as mud

 

the white wire runs from the tachometer to the coil. it is silly that AAW uses a white wire when 95% of tach makers use a green wire for the signal from the coil.

 

My General Motors Ramjet wiring harness uses a white wire for the analog tach signal.

3300, there is a white wire from the fuse block that is used for the wiper motor switch.

 

If you happen to have something like an MSD box, you need to tap into the sensor wire on the distributor. Attaching it to the coil may fry your tach.

 

MSD boxes have a tach signal wire.

 

you are correct but you will look long and hard to find a tachometer that has a white signal wire, it is most commonly green and the white wire is for the light inside the tachometer.

 

As a minimalist, I'd hate to see you run an extra wire if there's one in the new AAW harness that's meant for the job.
Do you have a schematic or wiring diagram for the new harness? That should help sort out what you're looking at.