I just put a new hitch on my 01 Durango. I went and bought a Hoppy 42215 plug in wiring harness. This harness plugs directly in to the tail light wiring without any splicing. The wiring works perfectly unitl I turn on the parking lights. At that point I have parking lights on the trailer, but no brake lights or turn signals. I have talked to Hoppy and the dealership, and they are not sure what is happening. Please help.