GMC Wiring Harness

[bdmcgee]

I just got off the phone with Early Classsic Enterprise. Nice guy. Seems to be a solid company. Anway, he told me the wiring harness is DIFFERENT in the Chevy and GMC? That's what he was told by the company who makes the harnesses. So, they DON'T have the dash harness for the GMC. Says it's not made. Has anyone heard of this? Will a Chevy harness fit into a GMC? I can't hardly believe it wouldn't. He said it was because of the duel headlights on the GMC. . .

As always. . any help is GREATLY appriciated guys

[57sailplane]

if its just the dual headlights thats nothing. the center 2 are just high beams so all you have to do is clip the plug off the Chevy harness wire the outside lights to the low beam and the center lights to the high beam and wallah! oh and ground both.. basicly if you have the plugs and wire to the gmc all you have to do is clip the wire were both go togather in the harness usally a few inches away from the low beam and splice to your new harness then wrap with eletrical tape of course i would solder the conections.

[Ackattack]

I used a regular painless wiring kit for my GMC. I think I just had to tap into a wire or two for the dual headlights.

I don't see how the dash harness would be any different.

[rogergodding]

I rewired mine with an EZwiring harness. I ripped out all of the old wires from the fuse block outward. EZ has to be the best one out there. Having all the wires labeled is a big plus......

[70' GMC]

Originally Posted by rogergodding

I rewired mine with an EZwiring harness. I ripped out all of the old wires from the fuse block outward. EZ has to be the best one out there. Having all the wires labeled is a big plus......

is there a website?

[rogergodding]

Originally Posted by 70' GMC

is there a website?

should be, I'll check.

[rogergodding]

here ya go: http://www.ezwiring.com/

it cannot be made any easier..... I've used two of them.

[John H.]

I have a factory GMC wiring diagram book for trucks built after August 12, 1968. I could photocopy the motor/light harnesses and fax you a copy. You could compare them to a chevy diagram where they go into the dash block. If colors and routing are the same, this would answer your question. Why would the dash harness be different? The cluster and interior electrical is the same on the inside.

I will soon find out as I have replaced my dash harness with a reproduction dash harness. I unwrapped my GMC and it was the same. I actually bought a harness without the gauges (cheap on Ebay) and converted it to the gauge style. There are 1 or 2 wires you need to take off the ign to the cluster that provide the lights to light up when you turn your truck on. I think I relocated a couple pins in the cluster plug too.

Good luck.

[13lazer]

the best way to rewire these trucks is to get a few donor harnesses from ebay or the junkyard. lay the harni out on a table and repair the best one with pieces from the other ones. look for burned wires and corrosion at the plugs. i once got a boxfull of good factory wires and connectors out of a junked 1977 chevette. use solder and heat shrink, chevy trucks are very easy to rewire.

[mshirey]

Try these guys they should have what you need. http://www.wiringharness.com/

I used their products and they are good quality and good fit.

[Musclerodz]

Dash harness is the same. Front light harness is different. The other issue is how the truck is optioned. There is the possibilty of several different part numbers depending on how your truck is equipped. AAW makes all the factory harnesses for the GMC and we are a dealer for them.

Mike