The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 72 GMC 2500

Bigblock50 · 09-19-2020, 05:23 PM

Go up to the second entry in this thread by Geezer 99. I’m using the color diagrams at that link. GMC and Chevy use identical wiring.

It looks to me like the yellow lead ends up beneath the HEI distributor, an aftermarket addition by the PO. I think the HEI units need continuous 12v to function. If so, this lead might provide that. Tomorrow I plan to trace the wire carefully under the HEI unit.

09-19-2020, 05:23 PM	#12
Bigblock50 Registered User Join Date: Aug 2020 Location: Luray, VA Posts: 35	Re: 72 GMC 2500 - electrically dead! Go up to the second entry in this thread by Geezer 99. I’m using the color diagrams at that link. GMC and Chevy use identical wiring. It looks to me like the yellow lead ends up beneath the HEI distributor, an aftermarket addition by the PO. I think the HEI units need continuous 12v to function. If so, this lead might provide that. Tomorrow I plan to trace the wire carefully under the HEI unit.