Hi again,
The tacho in my 79 doesn't work, the last time I got on here for this problem I was advised to get a tach filter which I ordered from ecklers, a few weeks later (I live in the united kingdom) said filter arrives and I fit as per the instructions, fire up the engine and No movement of the needle. The original filter had been cut out that is certain. I now have the dash in bits and the clocks out. The circuit board has no obvious signs of burning or breaks how can I test the system to find out what the problem is. I can only think of three areas to consider
1) the pulse/current from the distributor is not working
2) the curcuit board is infact not well even though it looks ok
3) the tach itself is faulty.
Any help would be great.

The tach on my 75 was not working when I first bought it. The tach circuit board was the problem and I ordered a new board. Since I never had a working tach, it was a shot in the dark that this was the problem. In my case, installing a new circuit board fixed my issue. You will probally not have any obvious burning on a bad board. Probally a rectifier or diode gone bad. Unless you know what the reading are supposed to be, you wouldn't be able to determine if the board was bad or good. New board was less than $50 US.

Get a tachometer use for engine diagnosis. A cheap one will do. Ground the ground lead anywhere you have good contact. Now use the tach lead to touch different parts of the circuit. If the tach reads the circuit is okay at that point. You can follow it to the point where it quits working, and you found you problem.

Ken Styer

Thanks for the help,
Checked things further and do need a new board, seen them on ebay but the seller will not post to europe. Do you know of any companies that make/sell the board that I could buy from directly?

Corvette Central lists the tach circuit board for your car. Their price is $61.15 and they do ship internationally. I would think the other major Vette suppliers would have comparable prices and shipping.

I've found Corvette Central is generally among the least expensive suppliers and I've never had a problem with their service.

Sublime,
Hi I'm in the UK too, and recently bought a tacho board for my 80, from a company called redline http://www.redlineg.com/. Give em a bell, the main man there was really helpful and friendly. It cost about sixty quid for the board and the postage, and the quality was good. I checked the calibration on a garage's engine analyser (the sort that uses an inductive type pickup to read and show rpm), and it was spot on. Highly recommended, best of luck with it!