dustinsandwich

I appreciate it. I'm beginning to suspect that I'm going to have to comprehensively go through this harness and put everything to stock, piece by piece.

Where does the ground at the relay attach to the body?

Okay, I got the fuse block wires soldered to their correct factory pairs. It looks like the only bypass was the radio, which was just barely twisted and taped. Explains the inconsistent radio power. I went looking for the fusible link, and it looks like maybe it burned out and was replaced with wire. I'm not sure:

I appreciate it, but I already got a 1984 FSM.

Yes, there's a black wire that grounds directly behind the turn signal flasher that's been cut, I suspect this should be going to the relay. I meant relay when I wrote connector. It's the black wire in this pic: Is that where the headlight relay grounds out?

It's connected to two green/blue wires, which might have more splices under the insulation

Okay, this is good, narrowing it down. I think the cut ground under the steering wheel must go to connector 121M on the headlight circuit. I see also that there's a ground at the negative terminal, which has been cut on my truck. I'll wire these to ground and see if that improves things.

Oh, I misunderstood. The cut ground wire is in front of the flasher units in the pic.

That... is bizarre. Maybe for redundancy?

I actually managed to score a correct year FSM for $20 on ebay. Trouble is, I'm used to old school wiring diagrams with the whole loom laid out and this doesn't have the wire colors in the fold out diagram in the back, just references to individual parts. So I'm having a hard time tracing from wire to function and finding grounds.

That's good to know thank you, except the flasher switch is hooked up and working. Except on the passenger side, same as turn signals. Should I bridge these and see if it makes the passenger signals work?

Correction, all bulbs are dim except driver's side main light.

Okay, I soldered the Green wire to its corresponding cut wire. It seems to be the horn, thanks to EDM620. Horn still doesn't work, but I'm thinking that these unconnected wires might have something to do with that: That was the random red wire, which goes behind the steering wheel. I think I may have to take the wheel off and see if they jumped the connector or something. Headlights are now doing this: Lights on (dim in both brights bulbs, lit on drivers) Brights on I also found another cut ground, I think: Not sure where it's pair is.

That's my plan, the only problem I have is the first electrician made some splices that don't make sense to me. There are two green/blue wires that might go together, but I'm not sure because they both come from the some side of the loom, and then a red/yellow which has a splice into it. i don't know where these are supposed to go, though when i bridged them the running lights came on.

Yeah, I'm learning a ton already. I'm planing on putting a completely independent fuse block on for aftermarket accessories after returning the wiring to stock to avoid this mess in the future.