No Voltage on Running Light Circuit of 7-Way Trailer Connector on 2007 Dodge Durango

Question:

my issue is that my trailer running lights do not work on the trailer. when trying another vehicle, they seem to be fine. both directional and brake lights work. When testing the plug on the 7 way and 4 way plug, using a light tester, I get power with brakes, and directional but no running lights. I changed the connector module where the trailer connector and still no luck. any ideas what might be causing the issue? thanks

asked by: Vinnie G

Expert Reply:

It sounds like you've successfully eliminated the trailer wiring as being the cause of the problem. Since you've tested the trailer connector on the vehicle, and found everything but the running light circuit working correctly, I believe you have a blown fuse.

According to the online copy of your owners manual, the fuse for the 'Trailer Tow Park Lamps' is in the Integrated Power Module box in the engine compartment next to the driver's side fender. There's two black boxes with removable covers, the box you need is the smaller one closer to the front of the vehicle. The fuse you need to check is in location number 9. You can see a diagram of the box location on page 405 of your owner's manual.

Once the fuse is replaced, before plugging in the trailer, you need to find out WHY the fuse blew. Check the running light circuit on the trailer (usually the brown wire) and trace it from the trailer connector to the taillights. Look for loose connections, pinched wires, or worn or cracked wire insulation that would allow the copper wire inside to short out on the trailer frame.

expert reply by: Mike L