someone help!!! i need a switch

[shadetree]

Pick up the 12v feed to the compressor motor, after the pressure switch. It's hot only when the comp is running.

Correct. This is where the ammeter or light will go. Really no need for an ammeter if all he wants to know if the compressor is on. Just use a light in the circuit from the pressure switch to the compressor. I posted this earlier. Don't know where the damn post went.shady

 

[calypso93]

Found what looks like independant switch/indicator assemblies at this place.
You may have to look at non-automotive electrical suppliers to find stuff.

www.action-electronics.com/pdf/gcsw22.pdf