Re: 73-87 wiring diagrams
 

Look in my signature. I posted all the 1973-1991 GM Light Truck wiring diagrams except 1981, 82 & 84. 1981 & 1982 are in the back of the service manuals. I don't have an 84 wiring diagram.

Re: 73-87 wiring diagrams
 

Thank you for that. It shows exactly what i was looking for.

Re: 73-87 wiring diagrams
 

Don't mean to jack this thread. I may have missed it, but does anyone have a the factory radio wiring diagram for a 76 half ton? I'm looking for the wires coming from the truck going to the radio. I have 5 wires right now...one plug with two wires (one light green and one black), and another plug with three wires (one gray, one yellow, and one black). I suspect the green and black are for the speaker?

Thanks in advance!

Re: 73-87 wiring diagrams
 

Disregard. I answered my own question!:metal:

Re: 73-87 wiring diagrams
 

[ignore: the thread I referenced did get mentioned]

Alex.

Re: 73-87 wiring diagrams
 

is there a difference between the years of the diagrams like 1973-1977?

Re: 73-87 wiring diagrams
 

There will be some differences as GM improved and just plain changed things. 73-75 has an ammeter in the dash. 76 had voltmeter and mechanical oil pressure gauge, 77-91 has electric oil pressure and voltmeter, 73-82 had floor mounted dimmer and 83-91 on the column... Other systems remained pretty close over the entire 73-91 run.

It's best to get the diagram for your year. They're reasonably small files so download and look a few of them over. 81 & 82 truncated diagrams are in the service manuals combined with the 80 & 83 full diagrams you'll be able to muddle through... '84 the is same way '83 & '85 diagrams should get you close enough to fix the problem.

I'd love to get a couple quality hours with my laptop, sheetfeed scanner, staple remover, and the fullsize GM light truck 81, 82, & 84 diagrams. If anyone in New England, San Francisco Bay area, or the Salt Lake valley has a set I'd like to talk about a short loan. The wiring manuals are stapled so they can be disassembled and re-assembled given the proper care.

Re: 73-87 wiring diagrams
 

thanks for the info. one quick question how about between a Chevy and GMC is it still the same? just difference name? i have a 1977 Gmc pick up.

Re: 73-87 wiring diagrams
 

I am changing cabs from a 1985 chev k10 to a 1982 k20, is there anything that should concern me. I know the wiper switch and maybe the cruise control are different. Hopefully the plugs will be the same.

Re: 73-87 wiring diagrams
 

Does anyone have the diagram for a 1986 c10 instrument cluster without gauges? Trying to figure out what wire number on the cluster connection equals what.

Re: 73-87 wiring diagrams
 

The Electrical FAQ has cheatsheets with this exact information. http://67-72chevytrucks.com/vboard/s...51&postcount=2
The 1986 GM wiring diagrams in my signature will as well.

Re: 73-87 wiring diagrams
 

I have a 1982 GMC 2500 with a 6.2 Diesel in it. I have a question in regard to voltage drops. When i push on the brakes, the ampmeter goes into a discharge. It isn't in the brake lights as i have unplugged the switch and tried it and it still does it. One thing that does happen when this occurrs is the glowplug light comes up real dim and the head lights also dim some. It has a new alternator on it, a new glow plug relay, and I have repaired about a dozen wires with failing insulation on them. THis only occurrs when driving forward and braking.it wont do it sitting still or in reverse. Ive been looking for the cause of this for two weeks and still haven't found anything . Has anyone else ever expierienced this before? The only thing I have yet to replace is the Glow plug controller. Could this cause a discharge like this?

Re: 73-87 wiring diagrams
 

Okay guys, wanna help? I need a Wire Diagram for a 1973 - 1980 then Convert it to a 1989 K20.. I have 3 different trucks in 1 so wiring this to work is pretty hard. I have a I-6 under the hood but cant get a response out of the motor due to something not hooking up right can yall help?

Re: 73-87 wiring diagrams
 

I'll get yall a photo of their work. Its Quiet Funny, But I seem to have Lights, Window Wipers & turn Signals, With Running Lights working Correctly.