Trailer Lights Do Not Work When Headlights Are Turned On on a 2011 Jeep Compass

Question:

I have a 2011 Seadoo iCatch trailer made by karavan. when it is hooked up to my Jeep everything works as it should, brakes, blinkers, hazards and running lights. the moment i turn on the vehicle lights i lose everything but the front running lights on the trailer. More info - uhaul did a crap job installing the wiring and it wore through and shorted the box. replaced that kit with a hopkins one from autozone yes i know..needed it quick. tested all connections for power and all were good. once the trailer was hooked up i had a weak blinker on the passenger side. changed the bulb and at the time it didnt change. buddy said bulb may be in backwards its an 1197 dual filament. rotated it and moved to the driver side which i found the bulb was fused to the socket with corrosion. so i left it be. just for grins i hooked everything up to the jeep and saw the weak blinker on the passenger side was good to go but now im at the the original description up top. i did notice with these tail lights the ground is riveted on a metal plate inside the housing. i have ordered kit TLL56RK and some barrel connectors. i will snag some heat shrink local to me but what am i missing here? can having the car lights on cause a big enough load that the corrosion on that one light is making the rest of the system not work?

asked by: Andy

Expert Reply:

Yes, I believe that that corroded bulb is something that is affecting the lights on the trailer. There is definitely a ground issue. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light.

Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces.

The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.

expert reply by: Michael H