Thanks for the offer Billy22Bob. I ordered a new one this morning ~ $165 shipped. Not in "winter mode". Maybe I am having a "senior moment" and the SC is fine. Unplugging the clutch is a good idea to be sure. I metered the air pump wiring is ok and motor reads ~ 0.2 ohms. Air pumps are ~ $750 new. I jumpered the air pump direct from the battery via a 40 amp fuse and ran it for 30 seconds. At this point I am concluding the RCM relay was a piece of junk from day one. If I smoke the new one at least I will have 4 spare relays to make repairs.
Semlinger would the SC work with the air pump not working? It probably would, I don't know? The CEL has never came on and I have driven at least 200 miles like this. When I install the new RCM I will post the results........Thanks for the help