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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: Dbutl007 on August 31, 2015, 12:02:59 pm

Title: 79 wiring harnes used in an 85
Post by: Dbutl007 on August 31, 2015, 12:02:59 pm

Will a 79 wiring harness (under the hood section) work on an 85. My wiring under the hood of my 85 is a mess. The best wiring harness ive found is from a 79. Can anyone tell me the differences between the two. Besides the dual headlights on my 85.

Title: Re: 79 wiring harnes used in an 85
Post by: 1967KaiserM715 on August 31, 2015, 01:14:07 pm

Not an expert, but I would say lights(obvious) Would depend on alternator setup, if the 79 had HEI you would be fine,if not, extra wire. Electric choke circuit I believe was not introduced till 81?

The last thing I would NOT know is wether the firewall plug changed, oh and AC and emissions stuff

Kind of vague I guess, but should get you moving in the right direction, I was just looking at harnesses last night, and didn't see anything for after 82, for whatever reason

Title: Re: 79 wiring harnes used in an 85
Post by: Captkaos on September 04, 2015, 04:09:09 pm

Complete or just the underhood? 
If just underhood check the pinouts before plugging it in.  Things moved in 1981.
The ESC will be eliminated and if you have cruise the wiring is different.

Title: Re: 79 wiring harnes used in an 85
Post by: Irish_Alley on September 04, 2015, 07:50:12 pm

imo you will be better off redoing your 85. dont know when but i know the firewall connection changed may not effect you at all but i noticed it in my 91