Thanks John&Joey, actually, I by-passed all the electrics by just plugging in the heater to 120vac and ran overnight. It froze up at first, but by morning had stopped cooling. This tells me for sure I have a blockage in the sealed system. This type cooling system has a refrigerant that can form crystals and thus a blockage, like a stroke caused by a clot in our bloodstream. To my knowledge, this rig has never operated out of level, which is suppose to be the cause of this issue. Regardless, it is nine years old, or thereabouts, and the life of these units is commonly between 8-10 years. I am not surprised, just sorry I didn't find the true cause before I had shot gunned a couple hundred dollars of replacement parts into the unsuccessful repair.