I got the digital tach amp from techguy quite a few months ago. It has worked perfectly but I have what I think is a glow plug issue that is somehow causing this nifty amp to try to tell me something.

When I turn the key to pre-glow; everything functions as normal. Light on for about 15 seconds and a perfect start every time. A few minutes into the drive the glow plug light comes on and the tach immediately swings over and points directly at 6. It will do this for the remainder of the drive. At the next start; everything works as designed.......or possibly it will repeat the tach swing and glow plug light. It's random.

I've put a meter on the plugs while (engine running) the light is on and tach is pegged and I get no volts. I have also checked for voltage at each plug while doing a normal pre-glow...all have proper voltage. Seems to be doing its job properly.

I'm stumped. Everything seems to work but I'm getting this strange behavior. Is there some diagnostic feature in the tach amp that's trying to tell me something? It's about to get cold and the glow cycle is going to be super important in a few weeks.

Sam

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Best Regards,
Sam

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