molldog12

I am trying to change the tach board in my 78 vette. I removed the speedo/tach gauges and its not on the back of the gauges. Is it located inside the tach or some where else?

Dirtbuster1

If you remove the front clear plastic from the gauges, you can remove the tach from the front. There is either 3 or 4 screws that hold it in. Pay attention to the screws on the board it self when removing it. There are some plastic spacers that keep it from grounding out.

molldog12

Thanks for the info. I have it out now. how do you know if it is good or not?

Dirtbuster1

What was wrong with it to start with?

It it is bad, there are usually heat traces on the back of the PCB.

molldog12

The tach has never worked since I have owned the car. I read that it is usually the tach board.

gbags

My tach never worked right it always was pegged and when I let off it came up a little bit. When I pulled it it had a burn area like when a fuse blows. I changed it and all is good. When changing pay special mind to where each nut and screw comes from. Return them back in the same pattern to work properly.

molldog12

I had my tach board checked today, It is bad. Where is the best place to purchase a new calibrated 78 vette tach board?

1Z87L8

send your original to George "ACECO" on this list
and have it repaired and calibrated.
he did mine just under 2 years ago and has done
a number of them for the guys here on the forum.

molldog12

thanks

0Willcox Corvette

If you want to just repair your board, we have them in stock ready for shipment. These boards are pre-tested and all you have to do is intall it in your old tach. It takes about 5 minutes if you have the tach out of the car.

Here is the link. http://willcoxcorvette.com/product_i...ducts_id=24036

molldog12

Install a new calibrated Tach board today and the tach works like champ. The only problem I have now is the lights in the speedo/tach display no longer work. I must of damaged the rear circut board when I took out the speedo/tach assembly. (Just my Luck) Has anyone ever hard wired the lights to bypass the circut board or do I need to spend $100. with shipping for a new board?

0Willcox Corvette

The fingers on the back of the board may have come loose from the plastic. Pull the center cluster out again and check this. When they come loose you can plug in the connector and push one over to the side while installing. It may just be as simple as putting some glue on it to hold it in place.

No need to hard wire the lights. If the circuit is bad you will see it when you remove the housing. If you do need one, we have them in stock.

44235W-X2417F 1978-1982 Speedo and Tach Printed Circuit 78-82 $44.00

http://willcoxcorvette.com/product_i...ducts_id=25310