Troubleshooting Jayco Popup Camper Brakes and Tail Light Turn Signals

Question:

I recently bought a 2000 Jayco Qwest 10x. Seller could not find the harness adapter, so I wasnt able to check the electrical, but everything else was beautiful so I trusted it was good. Brought it home, purchased the adapter, and have had nothing but trouble with the brake/turn signal lights, although running/parking lights work without issue. Heres what it does: in order to get said lights to work. I have to take each bulb out, turn it every which way while pressed against the socket, and eventually it will decide to light, so I quickly press it into the socket. As long as I keep them on/blinking, they continue to light as they should. Turn off hazards/brake for 2-5 seconds and theyll work again. Turn off for 5-10 seconds and they will NOT come back on. One side may light, then it will stop working and the other side will decide to come one. There is no rhyme or reason. I took a recent 80 mile trip and had to stop frequently to check lights, and every time they were not working. My van harness and the camper harness both have been tested good by local Jayco dealer. I have tried at least 8 different bulbs including 4 brand new, cleaned the sockets/connectors, rewired both light fixtures to camper wiring even though there was zero corrosion, checked the wiring from the tongue terminal block all the way back. I replaced the front and rear frame ground terminals rusted and the problem persists. What am I missing? I am beside myself with this fiasco! We are about to embark on a 1000 mile trip and have no reliable brake lights. TV is a 05 Pontiac Montana. Please help! Thank you in advance.

asked by: Mike

Expert Reply:

Your trailer light functioning sporadically and the lack of function at other times leads me to believe there is a power issue. It sounds like there is a ground connection issue, but it could also be that there is a power supply issue. I recommend testing your wiring using an incandescent circuit tester like # PTW2993. Some testers will utilize LED lights that don't draw the same power as incandescent bulbs so they may give you a false reading on power. Double check the ground on your vehicle side wiring harness to make sure you have a bare metal to metal connection because you may be getting enough power for signal when tested but not enough for function.

I recommend testing the wires at your tail lights for function. If the wires are working correctly there, then you either have a bad ground which can often look good but not be a good enough bare metal to metal connection or be lacking the power you need. I've attached a wiring diagram to assist. It is very likely a ground connection issue that can be at the main connection to your harness, at the junction box, or at the tail light assembly. Most tail lights use the mounting hardware as a ground, but at times another wire is needed to connect to a better grounding point on the trailer frame.

If you are having power issues, I recommend # 16-1-1 wire for all light functions and # 10-1-1 for trailer brakes, 12V power, and Ground. It sounds like you have a circuit breaker that is cycling as they work then don't and then do again. You may want to simply rewire your trailer to avoid issue.

expert reply by: Jason S