75 tack
Thread Starter
Race Director
Joined: Jan 2007
Posts: 10,700
Likes: 697
From: Danville Illinois
2025 Corvette of the Year Finalist - Modified
2024 C3 of the Year Winner - Modified
2021 C3 of the Year Finalist - Modified
2019 C3 of Year Finalist (appearance mods)
75 tack
The tack stays at 1,200 rpm with engine off, when running the tack goes to 1,700 rpm, no higher or lower at any time.
Since it does move somewhat i think it's not completely dead. are there any in line fuses or resistors ?
Need some guidance here !
Thank you in advance
Since it does move somewhat i think it's not completely dead. are there any in line fuses or resistors ?
Need some guidance here !
Thank you in advance
Race Director
Joined: Oct 2000
Posts: 12,710
Likes: 3,163
From: Shamong, NJ
The problem is most likely the tach circuit board. This is a common problem with 75-82 electronic tachs. Repro boards are available for about $60.00. You can pull the tach and replace it yourself, the boards come with instructions on replacing the board and zeroing the tach. You can also send it out and have it replaced for about $125.00 to 150.00.
Even when off, these tachs don't usually rest at zero.
Even when off, these tachs don't usually rest at zero.
