Trailer Lighting Troubleshooting On 2002 Dodge Ram 2500 Diesel

Question:

Hi there, I have a 2002 Ram 2500 diesel, with a 2014 16 ft car hauler. All the lights on the trailer were going out if I applied the brakes, and when I was putting a left signal on, the markers would flash opposite to the signal. I drove it into my shop and all the lights went out. The 7 way on the trailer was cracked so I replaced it, and still nothing. Now the 7 way on the truck has no power using a test light and it was replaced about a year ago that I bought from you guys. Now interestingly, the left taillight still turns on. And shut off with signal or brakes. All others still off. Also, I was loading my at plow, and the plow touched between the trailer and truck and there were sparks. The 1 taillight stays on the trailer even with the lights switched off and engine off. It goes off if I remove the fuse which means the fuse is OK. ..

asked by: Tejpal P

Expert Reply:

On your 2002 Dodge Ram 2500 Diesel, I recommend using your incandescent test light like # PTW2993 to check for functions at the factory connection that goes into your Multi-Plug T-One Connector Assembly for 7-Way & 4 Pole Trailer Connector # 20135. If you have functions at that plug, then replace the # 20135. If you don't have functions at the vehicle plug, and the fuses all check out according to your owners manual, then there is a problem with the factory harness. You would need a local shop to check out the harness.

If you have functions at your tail lights and don't want to replace a factory wiring harness, you can use the Tekonsha T-One # 118329 and the Universal Brake Controller Wiring # ETBC7 to get the functions of your 7-way connection and bypassing the factory system.

expert reply by: Jason S