I have a Fleetwood Expedition 36t. The dash a/c is not cooling. I added freon last year and it cooled fine for a few months but now it's no longer cooling. No fuse issues so I have to assume freon leak. I'm very familiar with automotive a/c systems and worked on or replaced various components several times. My question is are there any differences between a/c system in my RV and a typical automitive system? Other that 36' of hose from the compressor to the dash??