The power for the switches comes from the control head. If there is no power, go to the control head and see if the wire, brown, has power when the A/C is commanded on.
If it does, you have a wiring issue, if it does not, then the control head is bad.
Without the signals from the 2 pressure switches, the PCM will not ground the control side of the A/C relay for the compressor to come on.
Roy
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Saturday, May 9th, 2020 AT 1:54 AM