For standard cable TV service (at an RV Park or C/G) you use the *cable* inlet on the exterior of your RV... should be near (next to?)
the satellite inlet that you're currently connected to. Cable inlet may be unmarked...lost/missing sticker?
Confirm that your antenna booster is turned OFF, then re-scan the TV's (again, select "cable tv", as you mentioned)
If you aren't using a satellite system (your own dish & etc) then you won't use the satellite inlet.
EDIT: Ooops, sorry for the near duplicate reply... Hank posted while I was still typing!
Terri, the Chevy co-pilot