Yach Wire Andy, If I remember correctly, the tach wire is separate from the dash harness. It was an add on at the factory. I believe it is brown in color and attaches to the negative side of the coil. If you have the tach, you can run a separate wire by itself as a feed. Hope that helps. Larry
The distributor has been switched over to HEI. Not sure where the wire went. There is 1 wire coming out of the firewall by itself, to the right of the master cylinder thats not hooked to anything. Maybe thats it.
Larry is right on. On all the G.S.'s I have owned the Tach wire has always been dark brown and there is a seperate rubber gromet in the firewall by the master cylinder. The gromet is approx. 1.5" in diameter and is cone shaped. Wire was taped to existing wiring harness both in the dash and under the hood. Bill
Thats what I have coming out of firewall. I thought maybe it was for an underhood light at first. But is the factory tach compatible with HEI or not? And if the original brown wire went to the neg. side of the coil, would this be the same as the 'Tach' on the HEI? All after I trace it back to see where it comes from, of course.
The factory tach is compatible with an HEI. As a matter of fact, I have a 70 GS that looks like yours(Cornet Gold w/ Black vinyl top) that has a tach working with an HEI. And yes, the Tach connects to the HEI where it is labeled Tach. Should be an easy fix. Larry
Is there a reason they didn't just run it through the main harness connector?? I know it carries some pretty strong signals, and can kill the engine if grounded, but why the seperate wire for one gauge?? Seems odd. I am adding the factory tach to my ragtop, would clean things up if I could run it through and unused terminal connection on the firewall connector...easy to do. Later Tim