[Alan Anderson]

Your picture of the Spike shows its fuse still in place. Remove it and replace it with a 20A circuit breaker. The startup current for the compressor is high enough that you will blow a fuse eventually.

You haven't confirmed that the pressure switch is actually calling for the compressor to run. What is the state of the DIO2 indicator on the Dashboard? As a test, connect a wire directly across the terminals on the pressure switch to force the DIO input active.