Tachometer Help
Thread Starter
Drifting
Joined: Oct 2007
Posts: 1,458
Likes: 1
From: Collinsville MS
St. Jude Donor '08
Tachometer Help
Last night I went out to start my 78 and the battery was dead, when I turned the key on, the tach needle went all the way from 0 to 7000. I didnt think anything of it, just turned it back off and disconnected the battery and put it on the charger. After I put it back in and started it, the tach stayed at 7000 rpm, not moving. It fluctuates a little when I turn the ignition on or off. Anybody know caused this?
I have checked all the wires and everything seems tight. But I do have a drain on the battery and when I hook the batter up I can hear a clicking noise coming from the center of the dash?
I have checked all the wires and everything seems tight. But I do have a drain on the battery and when I hook the batter up I can hear a clicking noise coming from the center of the dash?
Burning Brakes
Joined: Jun 2005
Posts: 764
Likes: 2
From: THE OLDER I GET THE BETTER I WAS! NORTHERN ONTARIO
Sounds like the Tach circuit board quit...I just had the same problem a couple of weeks ago...I do not think it is related to the battery problem...when it's time for it to go it just does. I ordered mine from Dr. Rebuild they sell a pre calibrated curcuit board that is very good quality. but before you order that board check the tach feed wire from the distributor to make sure it is hooked up. If there is a Tach filter by pass it to see if the Tach will work....maybe you should do a search on the tach.... there is lots of good information in there. 
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
Thread Starter
Drifting
Joined: Oct 2007
Posts: 1,458
Likes: 1
From: Collinsville MS
St. Jude Donor '08
thanks for the help, I have to pull the dash anyway to replace it and now seems like a good time to rebuild all the instruments. I was really hoping it was just a fuse or grounding problem again.... I need a big reset button!
