[rvguy]

The 12 volt air compressor is used for keeping the small tanks filled with air so you can properly operate the air doors and the toilet ?

the 120 volt compressor is used to keep the entire air system at 120 psi when unit is parked and plugged in  ? Guess this can keep your coach level while chasing down those little air leaks..

Note:
Thank you for the info. This bus sat for 8 years. I was Jonny Rutherfords ( indy car drivers bus) I have been redoing it for 1 year now and its first real trip coming up in a few weeks. It has been thru a good shakedown, but will have a few more questions coming up. When all is done I will have a great write-up and summary of everything I have found out thry newell gurus and Newell.

[Richard]

Yes, that is correct. Most will just use the 120V if plugged in. The 12V is useful if boondocking to conserve battery life.

[Jonestead]

Adam, Look forward to hearing all about it

To elaborate on the topic, I understand that no 2 are the same, but some have similarities. Am I correct that the 12v is on generator street side? GAST i think, that makes an awful racket when running. Replace or rebuild?

I have found no 120v switch, but if I have a 120v compressor where was it typically mounted? I found what appears to be a compressor under the curbside air dump drain pipe for black tank in the aquahot bay that looks like it's plumbed to the expansion tank. I haven't studied it further than realizing it was there the other day (photo attached)

Thanks in advance

   

[Richard]

Arch,

The Gast mounted on the side of the generator is the 120V compressor.

The small compressor located by the curbside dump is the 12V compressor.

The 120V switch is typically located in the bank for switches located over the microwave.

[Jack Houpe]

I chased air leaks for a long time and fixed or removed the culprits causing them but my coach would still be unlevel the next morning. What really saved my bacon is rebuilding both 6 packs and putting green slime in my tag axle air bags, now the coach stays up for weeks. I just turn off the 120v compressor and leave the 12v one on just to keep the slide seals inflated. I also have the 120v black plastic cased compressor for anyone who would like to own it, replaced the brushes in it last winter.

[Jonestead]

Richard,
Kinda what I thought, but hat thru me the curve ball was the Gast is powered by the 12v labeled switch on the dash and that's the only compressor switch I've found

Jack, not sure what the 120v black plastic cased compressor is but would buying yours as replacement be a better option than trying to fix my Gast which needs attention

[rheavn]

"The 12 volt air compressor is used for keeping the small tanks filled with air"

The 12V air compressor only fills the small tank on the front wall of the drive wheels wheel well.  If you have a second small tank, like my coach, it is not filled by the 12V compressor.