compressor not cutting on

[1badPT]

My compressor for the first time in years has failed to cut on, despite me knowing that the tank is definitely low enough to cut the pressure switch in. The 30 amp fuse for the compressor is not blown. Could the pressure switch be bad? If so, what item number would I want to order? It is a viair 400 compressor(1)with a 5 gallon tank and the Big Red valves bought as the ride pro package that I no longer see on the online catalog due to the new arrival of the level pro packages, so I' m not really sure what to give for a kit number. Any help is appreciated.

[1badPT]

Can anybody help please. If the tank is low, should the voltage reading across the pressure switch read zero because the switch is closed in order to bring on the compressor? I would think that the only way to get a 12 volt reading across the terminals of the pressure switch with low tank pressure is for the switch remaining open, thus indicating the necessity to be replaced. Am I thinking about this correctly? Could my relay possibly be the problem? I' ve been working alot of overtime lately, and haven' t had time to even crawl under my car with a voltmeter, I' ve just been riding around, leaving it at ride height all the time. Just want to organize my approach. If somebody could tell me how to determine a problem with your relay, or even to determine if the compressor is blown, it is appreciated, just want to know what to look for.

[darren@ridetech.com]

The easiest way to check the pressure switch is to jump the two spades. If it kicks on then you pressure switch is bad. If not then it could be the relay or the pump. Check voltage at the pump to determine if the pump is bad.

[1badPT]

Thanks Darren. I jumped the spades and still the compressor didn' t kick in. I checked the voltage across the compressor and showed 12v indicating that the relay was operating correctly and an apparent open compressor winding, so I ordered my replacement compressor today. Thanks so much for helping.

[darren@ridetech.com]

I think that I talked to you....:)

[1badPT]

Oh, that was YOU?! How nice to place a voice with a forum name. Again, thanks a million Darren.

[1badPT]

Darren, I recieved my compressor yesterday and installed it today after work and figured while I was under there, I would mount it to a piece of MDF like you suggested to me a year or so ago as a possible solution to quiet the compressor, and wow, what a difference. I would have been laying on my back long ago had I known what a difference an 8" x4.5" piece of MDF makes. It turned the growl my compressor used to have into a purr. Thanks again for the excellent advice you gave me long ago on this forum

[darren@ridetech.com]

Sweet/:)