Having some AC trouble. System is full of 134. I ohm tested the compressor and it was out of spec so I replaced it now it tests in spec. I can get clutch to engage when I probe it. Does not engage when AC/Heater controls command it to. So I got a wiring diagram and I tested for continuity on all highlighted traces. All came back with good continuity except 1. Pin 85 on A/C clutch relay to Pin 1 on C3 Connector on PCM. This trace does not exist, meaning there is no pin on the connector nor on the harness side of the distribution box. As far as the diagram goes it says this one controls the relay, but it physically does not exist. "Experts" on just answer.com told me I am wrong and that theres no way it does not exist lol. I am leaning to believe that the AC/Heater controls need to be replaced, but am unsure.

 

There has to be a wire from the PCM to the relay because that is what turns the relay on

 

Sorry, pin 85 on relay is there, pin 87A there is no connector, but on c3 connector on ecm, pin 1 is not there. thats 100% true.

 

87A is used with 5 pin relays so you can safely ignore that pin. There should be a dark blue/orange wire going from pin 15 in the square connector in the PDC to pin 1 in PCM connector 3. If that's really missing I have no idea why. If the harness was manufactured without it the A/C would have not worked from day one. Any indication the harness was replaced at one point in time ?

Attached the pinout of the harness side at the PDC as it is weird connector.