So I picked up a 1980 pickup for $450 bucks, and as the saying goes, you get what you pay for. I had to do a good bit of work on the carb to get it to run right and now I've turned my attention to the wiring. From the looks of it, this truck has had 30 years worth of home-grown wiring. There is a lot of wires spliced together, connectors cut off, unprotected wires twisted together. It's a nightmare. The biggest problem I have right now is that there is either something shorted in the headlight switch or I have a bad ground problem. When the battery is hooked up if you turn the headlight switch on it almost acts like you turned on the ignition. The truck will start and run fine but the headlights don't work. I removed a really janky 4-pin trailer wire harness that was wired into the tail lights (badly, no converter). The ground wire was actually being held onto the frame by a hose clamp... yeah, I know. So my question is this, should I just try to change the headlight switch? I know the common answer is to check the grounds but where are the factory grounds on an 80? I have a factory wiring diagram but it doesn't tell you where they actually go. Any help is appreciated. I'm sure someone has prob run across this before.

 

Do you still have the wire diagram for the 1980? I am trying to figure out some wiring on my 80.

 

If you look at one of my links I found a really good link for the wiring diagrams on autozone.com after you log in and go to wiring diagrams.

The grounds can be made to any clean metal on the chassis. You can create a common ground area on the truck frame and put all the grounds there or put them on any unpainted metal. It's the positive wires that you need to worry about by just using a test light to verify what lights are coming on at what part HL switch.

 

also the wiring in the back of the haynes manual is pretty spot on for the 80.....but they do change up the haynes manuals from print date to print date. the headlight switch on the column is actually a grounding switch that turns on the park light relay and then the headlight relay. so there should be NO power to it. also the wires to that switch are like 20 ga and will melt if someone bypassed the relays and tried to run the full ground through them....