I have a 1999 Dodge Durango and can not get the running lites to operate on the attached camper or boat trailer. The hitch was factory installed and has worked up to recently. Both a boat and camper do not have trailer lites. I have 12 volts back to the relay in the rear of the Dodge Durango, and I have continuity from the relay to the connector pins, but I can not get 12 volts to the pins on the hitch connector. I have replaced the relay, but this did not correct the problem. My brake lites and signal lites operate fine. Can you tell me what you think the problem is?