Autometer Problems
 

Alright so the other day i get in my truck and start it and notice my tach wasnt working, so the next day i trying to figure out whats wrong. It has ignition power, ground, lights and coil power. I know it has igniton becuase the test light lights and it "adjusts" itself when it gets power. ive traced the coil wire and its got power as far as i can trace it. it's an hei, and ive tried in on a non hei on the camaro as well. so whats wrong? any help would be awesome. Thanks, Cole