I've got the a rev counter problem, sometimes it works, sometimes not, 72 XR-7. Presume its factory fitted, does not look like anything has been modified on it or the entire dash. Any ideas.
The car runs fine. I'm told the tack runs off the distributer, If so how is conected, because I just see the coil wire, and the posative lead from the coil that ataches to the distributer, and the ground leading from the coil.what colors are the wires running from the tack. From my crawling under the dash, mine look like they are red and yellow, but I'm not sure, they could be red and blue.
The tachometer is the power wire to your distributor or part of it I would say. Power comes from your ignition switch, goes through the tach and to the coil. Often the tachs will burn out and then to make the car driveable someone bypasses the tach wiring. The other thing that happens is the needle gets stuck by corrosion from a leaky windshield or cowl rust and the needle doesn't move.
So Jeff, has the tach worked since you have owned the car? Just asking, because mine wasn't and I found that it was bypassed like Royse said. I had taken it apart and resoldered the connections and spliced the resistance wire back properly and works fine now. Taking the dash off isn't that bad of a job after doing it a couple of times. The hardest part of removing the instrument panel the first time was taking the speedo cable off of the back of the speedo. I wasn't sure how to take it off and ended up braking the plastic coupling. Scott
The tack never has worked since I'v had the car. The problem isn't takeing the dash apart, its that the car is my daily driver and tearing it all apart poses as a problem. Although I could probley take off everything I dont need, and still be driveable. The speedo cable shouldn't be a problem I'v got the 1969 car shop manual, It tells how to take everything apart without breaking stuff.
Well today I tore the dash apart and wile trying to hook my speedo back up, I broke it. Let me tell you I was not the best person to be around at the time, I went and got some apoxey and glued the broken needle. after work about 1:30 AM I got home and found that the tach has been bypassed. I think I know wich wire it is.