So I'm just getting this guy in the backyard after picking it up next to nothing. It seems to run OK and everything with about 215,000 miles. My problems are in the electrical. I have no brake lights, no running lights, abs and ebrake light on when it's running. I am looking at the brake controller plug and it seems OK but I'm not sure. I'll install a new one shortly as I was told they are a common problem. Will that fix the running light issues as well or only the brake lights? Just so everyone knows I checked fuses and relays and they both are fine. Any help is always appreciated!

 

The "CAB" (controller antilock brake) could be the issue but I'd think more often it is the speed sensor at the rear axle. Check the resistance across the sensor if it tests "open" that's likely the problem.
Re the brake lights, do the rear turn signals work ? Does the center high stop light work ?
Re the running lights, are the running lights not working on all four corners ?

 

So the upper brake light isn't working either. No running lights work. I get turn signals all the way around as well as emergency flashers.

 

Ok, the wiring from the multifunction switch back to tail lights is not the issue. I'd start from the PDC, double check the fuse (5 unless the PDC is like 98 then it's C). Check with a test light or voltmeter, not just visually. Then pink/dark blue wire at the brake light switch should have power as well, and white/tan wire when pedal is pressed.
Does the truck have the pull switch or the rotary switch for the lights ? That changed somewhen around those years.

 

It's got the rotary style. And I think you're right about the wiring. I haven't seen anything burnt or broke off.

 

Update as follows, so I took contact cleaner and cleaned the entire fuse panel and rigged it all back up. That made a definite difference. That got all the lights to functionproperly! I'll definitely keep all the other ideas in mind that was said here. When those have problems I will know to check those.

 

So now that I have dash, running, and brake lights again on to the next. I still have the e brake and abs light on as well as something shorting out my power locks fuse. Does anyone here have some ideas on what will fix the's issues? Thanks again!

 

Take a wire stick it in pin 13 of the OBD2 plug, and ground the other end of the wire, and count how many times the ABS light flashes

 

So what will the number of flashes tell me?

 

IT flashes ABS codes, then you look up the codes, and it points you in the direction of what the problem is.