# 67 GTO Tach problem



## lms1077 (Mar 19, 2014)

Hello,
For the past month i have been trying to get my old tach repaired, but the part was on back order. Finally it came yesterday and I installed it right away.

However the happy ending i thought would come did not.

The new tach does not work at all. No movement.

I have the dash taken apart and just wanted to test the tach, so none of the other instruments in the cluster were hooked up.

When i started the car, and did not see the needle moving, i tried wiggling the wires a little and could feel a charge from the two black wires coming from the wiring harness.

In the attached pic, the old tach is on the left and the new one is the one screwed into the cluster.

If anyone can provide any advice I would appreciate it.


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## crustysack (Oct 5, 2008)

if there is no movement at all the you either have a bad new tach ( possible but unlikely) or a broken wire/ bad connection-( highly probably)- the ground wire is short and easy to eliminate, trace the 12v power wire and see if it is split somewhere or grounding out to the chassis/body some where, 40+ year old wires can break anywhere along the harness- put a voltmeter on the wire and see if you are getting anything- you can also try running a wire directly to your coil to see if the signal wire is no good


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