Posted by Chris (IP: 209.30.122.226) on October 27, 1999 at 19:17:39:
In Reply to: Tachs posted by Michael Haertel on October 27, 1999 at 18:49:28:
You hook up one wire to the positive, one to the ground, one positive for the light, and the last one goes to the hot wire on the coil.
Since the coil isn't getting any power when your car is off (wouldn't want to fire on a cylinder, now would you!!) the tach ought to go down to zero when it's correctly hooked up (even without the coil hooked up). Just for reference, the cap on my coil actually has a place to hook up a tach. Also,you have to have a pretty solid ground for the tach (i used my dashboard)--it wouldn't work for a while because the wire was only touching the dash, rather than being screwed down.