Can't Get Compressor to Run

[Mark McLeod]

How do you have the pressure switch wired?
It should be signal & ground, the outside wires of a PWM cable, no power.

To bypass it you can short across the pressure switch terminals. The compressor should turn on then.

[ColonelThrtyTwo]

Originally Posted by Mark McLeod

How do you have the pressure switch wired?
It should be signal & ground, the outside wires of a PWM cable, no power.

Yep

Originally Posted by Mark McLeod

To bypass it you can short across the pressure switch terminals. The compressor should turn on then.

Doesn't seem to work. The switch seems to be closed normally (without pressure), so shorting them wouldn't do anything afaik.

[Mark McLeod]

Originally Posted by ColonelThrtyTwo

The switch seems to be closed normally (without pressure), so shorting them wouldn't do anything afaik.

It just eliminates the switch as the cause of your problems.
It is closed below ~95psi, and open at ~115psi, remaining open until it drops below 95psi again.

So it's not the switch, since it's out of the picture when you short across it's terminals.

Does the Digital Sidecar have all three power lights bright green? Some times it's a lack of proper power, other times the DIO pins could be shorted improperly.

I assume the Relay indicator on the Sidecar is not turning green either.

After that it's most probably your code.