Welcome to the Corvette Forums at the Corvette Action Center!

How to replace the PC board on the speedo/tach panel of a 1980 C3.


New member
Sep 29, 2011
Orlando, FL
1980 Black coupe
I love this forum, it has saved me countless hours as I restore this 1980 Vette. I did find this post on another thread. Unfortunately I could have used a little more help on this project.
tach and speedo printed circuit boards.jpg
So here we go ....
I wanted to replace the PC board on my speedo/tach panel because the contacts for the plug were torn and the electrical system was playing all sorts of tricks on me.
In order to replace the PC board you have to first drop the steering column. Remove the panel holding the over-ride switch for the headlights. Then release the 9?16 bolts on the frame. Then release the tension by loosening the 1/2 inch bolts on the firewall. (Don't get them too loose or you will have trouble tightening them when the deed is done.) Now the steering column will drop allowing you to remove the lens over the gauges. This consists of 5 screws in the top and sides of the lens. Now you can remove the lens. This is a good time to wipe off the instruments and touch up anything that is scratched.
Next remove the gauge cluster by removing 3 screws along the top PLUS two small screws that come up from the bottom, aside the steering column in the bottom of the dash, they are well hidden. Now remove the speedometer cable from the speedo by depressing the spring clip and pulling it out of the back. Now you can carefully tease the cluster out of the dash. You will have to use a screw driver or other small flat tool to get the nubs on the sides out from the back of the dash pad. Now you will see the wiring clip in the center of the cluster. There is a clip on the top and the bottom of the plug that must be depressed to release this plug. WARNING if you are not replacing the PC board be careful to pull it straight out or you will damage the copper tabs necessitating the replacement of said board!
With the cluster out of the car you can twist out the dash bulbs and loosen the push pegs. Unfortunately the contacts for the tach are under 3 clips which must be removed from the other side of the housing. :mad First remove the black bezel from the front of the housing with a 3.5 cm Allen wrench (which you probably have never used before! This also will get you to the place where you can replace the tach PC Board if necessary.). To get at the clips remove the 3 1/4" screws holding the tachometer into the housing. Just pull the tach out as the three screws on the back of it are just in pressure clips. Now by depressing the spring clips you can force them out of the housing, Remove the clips and circuit board. Replace the circuit board in the reverse manner


Jan 17, 2004
1981 dark blue metallic
Welcome to CAC!!!!
you should have an assembly instruction manual,
as well as a factory service manual.....
these are the bible as to how these were built and repaired.:thumb

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors


MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!



Advertise with the Corvette Action Center!

Double Your Chances!


Top Bottom