No power to low pressure switch

If the compressor does not engage, we need to start at the relay. First thing to check is if jumping the relay from pin 30 to 87 and see if the compressor comes on. Then jump from 86 to 87 and see if the compressor comes on.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If the compressor comes on with both of these jumped then you do not have a fuse issue and either have a relay issue or a control issue.

So at this point, we need to check the PCM and if it is grounding the relay to energize it.

You do this by putting your red meter lead on battery positive and the black on pin 85 of the relay with the relay removed. Then turn the engine on and turn the A/C on. Does your meter read 12 volts or battery voltage?

If not then we have an issue with the PCM or one of the two pressure switches. If you jumped the low pressure switch and it does not come on then we need to check the AC pressure switch which is basically the high pressure switch.

This is not a simple switch that we can jump so we need to actually check the voltage on the sensor for each wire to find out what it is. You have a 5 volt reference, ground (low reference) and a signal wire. Please tell me what each voltage is on each wire.

Please find the wiring diagram below for this detail. Once we know what all these are, we can figure out next steps.

Please let me know what questions you have.

Thanks