Some have reported that the 12 volts at the plug is only present when the ignition is in the on position. I didn't have that problem but I cut the 12 volt wire going to the trailer plug and ran a 12 gauge wire to the plug from the starting batteries through an inline 10 amp fuse. I did that so that if there was a problem, I could get to easily as the wire and fuse were in the back right storage compartment where the batteries are located.
2016 Newmar Dutch Star 4369
Newmar Owners Club
USAF 1966-1969,- Law Enforcement 1969 - 2003, Retired since March 2003