Ok, I read the post that Trikar started on 12/20, but since I am more than a little dense, I was hoping for some clarifications. I am putting the GT gauges in my dash, where previously there was idiot gauges. I have run mech temp, volt, and oil with no problems. The question is the tach. This tach came out of a 72, which differs from the later tachs in that it has two wires (Ign & Coil) as compared to the later with 3 wires (has a ground wire). I tried testing it on top of the radiator by wiring to the neg on the coil and the battery. Not only did it not work, but it prevents the car from starting. Ehhh, not good. I think this tach is fine. So, I am not understanding this "shunt" business and was hoping someone can lay it out in super-stupid terms for me, such as "you connect the 'Coil' wire here and run the 'Ign' wire here." If I need to buy a shunt, no problem. If someone can tell me how to wire this baby I will be very grateful.
It wires in series with the coil I think it wires in on positive side of the coil if I remember correctly so hook the wire that is on the positive side of the coil to ign side of tach and coil back to positive side of coil .
Power to the coil runs through the tach. So the "Ign" side connects to the power supply. The "Coil" side connects to the positive side of the coil. Remember, if you test this with power from the battery, the engine will keep running until you disconnect power to the tach.
Clark, sorry to be so slow....help me out with the wiring. On the back of the tach, I wire the the 'Ign' lead to "X" and the 'Coil' lead to "X".
You have to find the light green (or blue) with red stripe on or around our steering column. You can cut it there or out behind your engine. I cut mine out behind my engine, in case I needed to bypass the tach. So no matter where you cut, you will splice in the IGN side towards your steering column. You will splice in the COIL side towards the + side of the coil. Again, I did mine out in the engine compartment and ran a red wire and a blue wire into the car to the tach. You need to have some provision to bypass it. If you lose your tach (usually an open or burned out d' arsenval coil) you will lose your ignition source to your coil, otherwise dead on the side of the road. If this has helped, I can tell you more. I've done mine and a friends. The friends was cut and installed with plugs under his dash. So you can see, I've done it both ways. Let me know. Hope this helps. Steve
Illuninance72, If you dig around in some past posts, I think I did a better job explaining this project, as well as how to hook up the ammeter without a GT wire harness. Steve
