Do you have a HWH, or Power gear/ Valid system?
My 08' Scepter with the Power gear/ Valid, has the compressor tucked up behind the entrance steps, and the air tank is accesable from the generator compartment, also on the passenger side.
From what I've read on this board, it seems most (or all) of the HWH systems have the compressor mounted around the rear drive axle.
Snowflakes they are
!!