Okay. That is showing that the module is not grounding the relay to turn the compressor on, but the compressor and wiring are able to turn on.
So, we need to get into the control side.
Let's start with the pressure switches. I would go to the dual pressure switch and check for voltage on pin 4 to start.
If you have voltage on this wire, then the cycling pressure switch is fine.
Then check for voltage on pin 1. This is the signal that is going to the PCM to tell it that the low pressure is fine. Then check voltage on pin 3. This is telling the PCM that the pressure is not too high.
Looks like these are all on/off switches so you should have 12 volts on all 3 wires with the engine running and A/C on when you back probe the connector with it plugged in.
If you want to bypass this dual pressure switch then you need to remove the connector, jump pin 1 to pin 4 and then apply 12 volts to pin 3.
If the compressor comes on, then this switch is the issue.
Images (Click to enlarge)
Saturday, October 9th, 2021 AT 10:49 AM