tach problems
Thread Starter
Instructor
Joined: Jun 2006
Posts: 116
Likes: 0
From: Prairie Village Kansas
tach problems
i just got my 79 a few days ago and the tachometer on it is not working and sits all the time at 2500 rpm. when i asked him (the guys i bought it from) about it. he said its been that way ever since he stored it in his barn for the winter and then some story about a mouse possibly nibbling on the cable and thats why it doesnt work...
what is the cheapest way i can fix this and if i cant where can i order a tach that looks similar to the stock spedo to fit in old tachs spot.
what is the cheapest way i can fix this and if i cant where can i order a tach that looks similar to the stock spedo to fit in old tachs spot.
Drifting
Joined: Nov 2003
Posts: 1,634
Likes: 4
From: Northern NJ
St. Jude Donor '04 & '05
It is likely either the tach filter or even more likely the tach printed circuit board itself that is the culprit. The tach board many times can be rebuilt for about half the cost of a replacement. And the tach filter can be inexpensively replaced if originality is not an issue, and more expensively if it is. 
I'd suggest you first bypass the tach filter to see if the issue lies there. If not then you get to take the dash apart to access the tach movement and printed circuit board. Sometimes the PCB and/or components are burnt which is obvious. However the board can also look just fine and still be non-operational. If you need more detailed info on tach troubleshooting and repair, please feel free to PM me.
Good Luck!
I'd suggest you first bypass the tach filter to see if the issue lies there. If not then you get to take the dash apart to access the tach movement and printed circuit board. Sometimes the PCB and/or components are burnt which is obvious. However the board can also look just fine and still be non-operational. If you need more detailed info on tach troubleshooting and repair, please feel free to PM me.
Good Luck!
Drifting
Joined: Nov 2003
Posts: 1,634
Likes: 4
From: Northern NJ
St. Jude Donor '04 & '05
Originally Posted by White79
Okay so im new to my vette and dont wanna go running around with a screwdriver taking **** apart....
so could you tell me what to do like in retard terms.lol
so could you tell me what to do like in retard terms.lol
Let us know what happens with the above test and we will "cross the next bridge" when/if we get to it.
Good Luck!
Regards...............George
Pro
Joined: Oct 2005
Posts: 581
Likes: 0
From: Boynton Beach Florida
check the fuse also..when you put power to the tach it should go to 0. if you pull the tach you will see on the circuit board 12v. gr. and input..put power and a ground to it and it should go to 0..then run a wire from the tach filter to input an the tach should read your rpm if that works start chasing the wiring from the printed circuit back
