Factory AC clutch magnet burned out. Replaced whole compressor. Pulled a vaccume and recharged. Ac clutch wont kick on. Changed high and low pressure switches and clutch relay. AC works when I pull the relay and jump the connections. Both pressure switches have 12v at the connector. Put new relay back in and still doesnt engage clutch. What should I look for next?

 

Relay is controlled by the PCM. When you set the controls to some flavor of a/c, the control head tells the pcm you want a/c, and it also sends power thru the pressure switch circuit. If the PCM sees both signals, it *should* trip the a/c clutch relay.

Verify the PCM is seeing 12 volts at the both the input from the control head, and from the pressure switches. If it is, with engine running, a/c on, see if the pcm is actually grounding pin 85 of the relay.

You can download the service manual for your truck from here. Wiring diagrams are in section 8W. Later in that section, will be connector pinouts, so you know which wires you need to test, where.

 

Did you put oil in new compressor as well?

 

Ya compressor came pre filled. Had ac running and cold air but only if I jump the relay.