[69GP1]

I bought what supposedly is the best repro tach on the market, and have trouble with erroneous readings and/or no reading at all. I sent it back, and they checked it out... said it was fine and returned it. It worked for while, then reverted to the same thing. I bought ANOTHER and tried that, but got the same results.

Since then, I read that the tachs won't work with some aftermarket ignition systems like Mallory, etc. I put Pertronix on my car. Could this be the problem?

It works fine at times, then gets erratic and sticks at 4000 RPM or shuts off. The ground is good, the light works perfectly. It's grounded to the horn really mount screw as per the factory diagram.

Are these repro tachs junk, or could it be my ignition?

Does anyone else have a hood tach and the Pertronix module?

Thanks...