Just bought a used 5th wheel with the Dometic RM2862 fridge. The lights were not working so i reset the heat stack circuit fuse and they came on. Then it would only run on gas and still not cool. I replaced the 5 amp 120v fuse as it was blown and it showed to be on AC but not cooling and eventually blew that fuse again and all lights are out again.... Any ideas? I greatly appreciate any help.