Gauge cluster grounding issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rdc72 · 07-28-2020, 12:17 PM

I hope someone can help me out on here? i have a 72 with factory tach and it stopped working. A little back story, i changed out the circuit board and replaced all the bulbs with LEDs, now the tach doesn't work and the lights that didnt work now work and the ones that didn't do? i have tried to put a ground from the back of cluster to the chassis, no go there too? i have tried everything to get this thing to work. any help would be much appreciated.

sick472 · 07-28-2020, 02:56 PM

I would clean up the contacts at the gage cluster to harness "U" shaped connector and at the back of the gage cluster where the harness connects to the circuit board. LED's need bright and shiny connections. I'm not sure about the tach issue. If all else fails, go back to incandescent bulbs to eliminate them as part of the problem.

custom10nut · 07-28-2020, 10:30 PM

The Tach is separate from the Circuit panel. Check you grounds on everything. These trucks LIVE for grounds

**davischevy** · 07-28-2020, 10:36 PM

Is the tach plugged in backwards? It can be done, but I won't devulge how I know.

07-28-2020, 12:17 PM	#1
rdc72 Registered User Join Date: Apr 2018 Location: Waynesville, MO Posts: 46	Gauge cluster grounding issues I hope someone can help me out on here? i have a 72 with factory tach and it stopped working. A little back story, i changed out the circuit board and replaced all the bulbs with LEDs, now the tach doesn't work and the lights that didnt work now work and the ones that didn't do? i have tried to put a ground from the back of cluster to the chassis, no go there too? i have tried everything to get this thing to work. any help would be much appreciated.

07-28-2020, 02:56 PM	#2
sick472 Registered User Join Date: Jul 2015 Location: Sedalia Mo. Posts: 1,130	Re: Gauge cluster grounding issues I would clean up the contacts at the gage cluster to harness "U" shaped connector and at the back of the gage cluster where the harness connects to the circuit board. LED's need bright and shiny connections. I'm not sure about the tach issue. If all else fails, go back to incandescent bulbs to eliminate them as part of the problem. __________________ He who is without oil shall throw the first rod. Compressions 8.7:1 1972 C10 1976 C10 (parts truck) 1985 K20

07-28-2020, 10:30 PM	#3
custom10nut Registered User Join Date: Apr 2015 Location: East Tn (In the heart of the Smoky Mtns) Posts: 1,846	Re: Gauge cluster grounding issues The Tach is separate from the Circuit panel. Check you grounds on everything. These trucks LIVE for grounds

07-28-2020, 10:36 PM	#4
davischevy Senior Member Join Date: Sep 2008 Location: Harrison, Arkansas Posts: 9,791	Re: Gauge cluster grounding issues Is the tach plugged in backwards? It can be done, but I won't devulge how I know. __________________ other Larry Build thread, Arkansas K10 https://67-72chevytrucks.com/vboard/...=755797&page=5 The ability to speak several languages is an asset, but the ability to keep your mouth shut in any language is priceless.



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