Pump runs intermittently after fill...

Once the tank refills and the pressure switch switches off the pump, it sometimes switches the pump back on intermittently for short one second bursts.

Bad pressure switch or are they just sensitive to minute pressure fluctuations?

Possilbe bad pressure switch or time delay…

what is ur complete setup?

you may want to check the terminals on your relays.I had a similar situation where they filled one time then the next time they wouldn’t I found that one of the wire terminals was barely hooked up.snapped it back on & was good to go. :smiley:

that or check to make sure you dont have any leaks in the system

Check all electrical connections - particularly your grounds… I doubt this is a pneumatic issue so much as an electrical one…

Viair 275c
SBD 1/2" valve
1/2" lines
6 gal tank
Unknown brand 1/4 NPT 2-wire pressure switch

will check all my contacts

It does have a small leak but since the switch fills to 145 and switches back on at 120 I don’t think that’s the issue.

no time delay

I think it may be a pressure switch issue but since its intermittent I’m not sure. What makes it even more puzzling is that it seems to be worse when its cold out and stops when the car warms up.
Will have to get a new pressure switch to see if that fixes it. Which brand is recommended?

well do this… have a psi gauge on ur tank… and fill it all the way up to 145psi… have someone blast the horns and watch where the psi drops too… if it falls below 120psi and ur compressors kick back on, then i believe everything is working just fine…

upgrade your compressor to a 400 or 450 or if you want that 200psi…480c