Dealer installed AC harnesses info

[pizzaman09]

My truck has dealer installed AC.  A forum member asked for how it was routed and where everything hooked up.  I decided to post this for reference to anyone that might be trying to add AC.

 

I took photos of the entire engine side harness. I started at the temp sensor and ended at the compressor.

 

 

 

You can actually see two temp sensors in the photo below, the dealer spliced into the lower radiator hose and put the sensor in that has the black braided wire covering. This was done because stock radiators without AC didn't come with a threaded port for this. As my Comanche had a newer radiator with the port I put in the other sensor which is now crusty green and has the red wire. Both are valid approaches.

 

Another wire from that end of the harness goes to the electric fan.

 

The harness was routed under the front of the air box to run near the driver's side of the engine bay. It's the corrugated plastic covered line I pulled up beside the air box here. 

 

Near the back of the air box there is a relay plugged in.

 

Detailed photo of said relay.

 

Right near this relay is where the dealer AC harnesses plugs into the truck harness. The truck harness is the big bundle of wires that runs over the drivers wheel well. Looks like it is grounded at the fender here too.

 

The part of the harness that goes to the other side of the engine bay is routed around the brake booster.

 

Up across the cowl, one zip tie held it to a wire harness it crosses.

 

It runs across the top of the rear of the valve cover and routes down right under the left edge of the expansion tank between the heater core hose and the bottom expansion tank hose it's the wire harness that has crusty yellow coolant on it under the expansion tank.

 

It then routes near the relays that are behind the ignition coil.

 

Right in the center of this picture the harness splits off two ways, one section goes down to the relay that is how in the next picture, the second leg goes across the ignition coil output over to the compressor and pressure switch.

 

The Bosch relay I just mentioned is mounted to the left of the other relays on the relay bar.

 

You can see the wire that goes over the ignition coil splits and one connector goes to the pressure switch and the other goes up the back of the compressor.

 

The compressor wires come up between the high and low ports and connect to the front of the compressor.