Factory Tach Won't Work

[Low69CST]

I had my truck together a few years ago and the tach worked fine. After a few years of sitting, my tach won't work. I have a painless wiring kit and a built 400 small block with a pertronix HEI. Everything appears to be hooked up fine. Is there anything simple I may be missing. It's possible someone may have took something apart and didn't put it back correctly. The wiring diagram has the purple/white wire going from the distributor to the tach. And I also have a yellow wire plugged into the tach. Does anyone have any ideas?

[HIGHWAY BY THE SEA]

Mine also stopped working mysteriously. I simply removed it from the truck and sent it to these people.

Willcox Corvette, Inc.

123 E. Maple Street*Jeffersonville,*indiana*47130*
800-588-3883

You may have to call and make sure they are willing to fix it. They typically work on Corvettes mostly, but occasionally they will work on these truck tachs as well. They are very friendly and very fast too. I got mine back in less than a week.

[davepl]

Mine also did not work with a Pertronix module in a stock body distributor. So I swapped it for a repro that a friend had and that works, so it was hit or miss. I do know with the Pertronix the low-RPM reporting can be off because it does multiple spark, sometimes that will skew it to read higher than actual.

[FlounderGDI]

I just put a factory tach into my 69 CST-10... It's supposed to ground to the cluster tin but mine wasn't. I ran another ground from a screw under the dash and up to the grounding lug on the tach and mine started working. Maybe checking your grounds and cleaning them up might help.