tach reads backwards!??.....
Thread Starter
6th Gear
Joined: Dec 2004
Posts: 6
Likes: 0
tach reads backwards!??.....
Maybe someone can explain this to me. My tach on my 76 had stopped functioning correctly and stuck at 3500rpms. So I replace the tach filter(which had a broken wire) with no change in the tach readout. So I tear out the dash and replace the tach circuit board (by visual inspection it had obviously fried). Now the tach starts at 3500rpm and jumps down to about 2500 when i rev the motor, then back to 3500 at idle. The tach never moves more that about 1000rpms. The ground seems solid on the back of the tach. I've run out of things to check. Any suggestions?
Thread Starter
6th Gear
Joined: Dec 2004
Posts: 6
Likes: 0
Yup, did that. The tach doesnt move over a full range of motion, backwards or not. It just moves slightly backwards when the motor is revved. Any suggestions after the filter and circuit board have been replaced?
Thanks for the reply.
Thanks for the reply.
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
what type ignition do you have. if it's stock, i don't know. with stuff like MSD, you often have to bypass the tach filter or it will run back wards. since you replaced the board after the filter you might try it.
