I am trying to wire up a factory tach to my buddies '64 Impala. The car did not originally come equipped with a factory tach. It has three wires coming off the back, one is to the lightbulb, one appears to be tied to the case, and the third I assume is the signal wire. I tied the lightbulb in with the rest of the dash lights, hooked the one that is connected to the case to a ground, and the third I hooked to the (-) side of the coil. The light works with the rest of the dash lights, but the needle does not move when the car is running. It is possible the tach does not work since it has been sitting in the attic of my dad's garage for 25 years. I just want to make sure I didn't make any wrong assumptions on the wiring, before I send the tach in to be reuilt. I have looked at two different wiring schemes for a 64 Chevy, but neither of them show a tach. Thanks for any help!!!
Sounds like you have it wired right. What colors are the wires? Should be black to ground. Make sure your ground is good.
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