AC clutch doesn't engage.

Voltage will appear all the way up to an open in a circuit. If the ground portion somewhere between the clutch and the battery is open, you will see 12 volt power on the ground side anywhere before the open since the clutch is not actually loading the circuit.

 

Start at the LP Switch and disregard the ground. Do you have power on one side only when you turn the AC on?

 

How hard to just start running new ground wire ? I would've already had a #### fit .

 

Is that with the ground wire plugged in I assume? If so, unplug the ground and recheck

Hold up, hold up,

 

No matter how effed up the wiring might be, a switch is just a switch. If low pressure is high enough, power should cross it no matter which side it came from

 

Switch plugged in or unplugged when you checked it?

 

There should be no power to the LP Switch with the AC off. That's why I asked if the ground at the clutch was connected. Sounds like it's backfeeding., though it shouldn't have power.

When you get back ti it, see if there's power still with the AC off, and ground unplugged.