Electrical Hell

need to be checking both of the front fuse panels (top and under the cup holder).... sounds like you have a relay going bad.....

 

Here are the schematics for your truck. Good luck.

 

********All most positive you have a gang plug that is gone. Why because one relay would not control the front and rear Ac. The yellow relay is the battery protection relay.. That shuts everything off so there is enough to start the motor.
On this forum people have talked about the big gang plug beside the steering column being green with corrosion. BEFORE I take that off and look and that's with batteries disconnected I would look on the schematic and note how many grounds there are. Each fing one can be bad and the will screw up the truck. Take sand paper , again BATTERY DISCONNECTED, and clean all the firewall grounds putting dielectric grease on clean terminals, then under the Heater, yeah the dash comes apart clean those. Unplug every gang plug you can find where dirty clean then put dielectric grease. Mine I found under the heater when I was changing the evaporator for Ac gange plugs that never got wet had green inside.

 

The trucks are well engineered, well thought out. But the assembly is cheap and the wiring is substandard. I've told by more then one dealer tell me if I keep it for ten years and it's already ten years old that I will need to replace harness because they are crap. Sorry my 41 year old mini has the same harness.

 

Just remembered reading in one of the forums that the maybe a hiden relay in behind the frig one guy also had where a factory installed screw went into the harness somewhere behind the seat or along the floor. Do you have the wiring diagram?