Any way to test an autometer tach??

[badmix]

My tach in my truck is stuck on 900rpm. I tested the red (power) its fine, the ground is good, the white (instrument light) is good. Is there anyway to test the green (going to coil). The tach does nothing weather I turn the truck on or off or fire it up and drive, nothing.

 

[BIG BROWN 79]

try cleaning up the connection on the coil.

 

[Russell]

If you've got continuity between the green wire and the negative side of your ignition coil, then it will be an internal problem with the tach. Maybe email autometer and see if they'll do anything for you?