[IRSd_mini]

What kind of adjustable presssure switch??? if its a kind like what AIM sells, not a square d one, then it kicks on at a 1 psi drop... so if you have ANY leaks, it will always be on.

I agree with this one. Also since you said it was blue and round, I bet it is an eai switch like someone else said. And they do not have a pressure differential in them. So even as the air cools in the tank, or the outside temp drops, it will start the comp back up. Those pressure switches are best used for engine driven comps.

 

[IRSd_mini]

The only solution for you is a different psi switch. If you want to get one kinda locally, call adam at pacific air technology in mission viejo. Phone #949 855 9343. Or look up a tool repair place or hardware store in your area. These are just the switches used on home air compressors.