RayVette2

I am new to forum and would like to first say hello. next get some advice. I have a 1980 corvette that has recently developed a non working tach. I have troubleshoot the unit according to a guide by Willcox corvette. I am getting power to the lugs behind the unit along with a good ground and continuity on the 3rd lug which is the signal lug. Also when I turn the key on the unit zero's itself our. the circuit board looks good, no dark marks. The distributor is giving out a signal since I put it on an external tach and can see the RPM's. I then used the same wire, going around the tach filter and still no movement on the inside tach. What now? Help!!!

JimLentz

Bypass the tach filter and see if the tach works that way.

RayVette2

Thanks. I have and even with a known source for the tach, because I hooked the wire to an external tach it still did not work