[Lee Dove]

Can someone tell me what this stainless covered box is? It's covering something electrical with a toggle switch on the side and I., think there are 4 of them on the rig. If you flip the toggle it sounds like it releases air.

[bikestuff]

Lee,

Can you add the vintage of your coach to your signature line? It would help folks to help you.

Bill

[HoosierDaddy]

I agree with Bill. My first wild guess would be an air leveling system component.

[Richard]

It could be the HWH control box. Do you have an HWH panel for leveling the coach?

But there would only be one.

[Lee Dove]

Updated signature and profile

[folivier]

I agree it does look like the HWH box but there should only be one like Richard said.  Not sure what the switch does unless it is an override for travel mode?
  Inside it would look like this:

[Richard]

Lee, you said when you flip the switch air escapes. Where does the air sound come from? Does the coach move when you do that?

[Lee Dove]

It sounds as if it exits under the coach

[Richard]

I am trying to help you, but more specificity is required.

Does the coach move at all downward?
Does the air sound come from between the front axles?
Does the sound come from around the drive and tag tires?
Does the sound stop on it's own, or just when you unflip the switch?

[Richard]

Any progress? @"Lee Dove"