These problems can be maddening. First, you eliminated the camper as a source of problems- that's half the battle. Sounds like you are losing ground, since no lights work. Are you familiar with a volt meter? If so, use it to check output of each pin on your Jeep connector one at a time. You will need someone to help with this-like stepping on the brake pedal while you check. If the wiring pigtail on your Jeep is one of those plug-in no splice kits, crawl under and un-plug the connections carefully to inspect for corrosion on the pins, since these usually get pretty nasty, and eventually start losing connection. (grease applied to them when they are new helps prevent this). It is possible that your connector uses a seperate ground wire that attaches to a metal part of the Jeep under the back somewhere. It could be broken, or corroded. Sometimes the trailer will get ground thru the hitch ball, but it is best to make sure the ground wire is intact on the tow vehicle for best performance.
Sorry for long post <img src="/forums/images/graemlins/scared.gif" alt="" /> Hope this helps,
Corona