ARB compressor issues. Can you diagnose it?

Any ideas why my ARB compressor would quit working? It started working intermittently about a month ago. Checked the pressure switch and that is not the problem. I can hear an internal switch clicking when giving and taking power away but no piston movement. I've tried tapping on it w/ a rubber mallet just in case it was stuck as the first time I noticed it wasn't working, it started when I dropped the hood. Electrical it seems to be all working. Tested w/ a meter and pulling the two wires off the pressure switch and contacting those together as prescribed in other thread. That's when you can hear the internal clicking. Can also hear it when manipulating the in cab switch when connected to the pressure switch. The locker is working as I was able to switch it on and off with the remaining air in the storage tank until it ran out. Hoping for a solution before I take it out and pull it apart, figure out what's wrong with it but can't put it back together because I broke something tearing it apart.




Or, ISO an ARB compressor for cheap.

 

More info might help, single or double? Have you checked voltage/connections both at the power source and compressor? Grounds checked and tightened?

 

Which compressor do you have?
The clicking you hear is a relay.
Where is the compressor mounted?

The relay isn't water / weather proof. Depending on where the compressor is mounted its possible that water got into the relays and started to corrode them.

 

Example