Trailer running lights not working

Hi Gang,

I have a 2008 4x4 DC with the 5.7 and factory towing package and tried to install a rear camera on my trailer the other day. I connected the camera to the running lights and pop goes the fuse?... All of the running lights and one of the turn lights were no longer working. (I had towed the trailer a week earlier and the lights were fine.) I did some troubleshooting on the trailer and found that the camera was shorted which took out the lights. OK, no problem, must be a fuse.

I checked every fuse under the hood and under the dash and found 1 - 10A fuse under the dash blown, but it didn't fix the problem. The weird thing is the 7 pin connector has running lights and brake lights/ turn signals, but the 4 pin connector has no running lights and a turn signal on just 1 side. I checked the connectors with a meter just to make sure I wasn't hallucinating.

Any thoughts on what I should look for? Are the 4 pin and the 7 pin connectors on different circuits? Is there a 3rd fuse location someplace?

Thanks for your help.

 

Trailer wiring is a 30a fuse,
Just had the same issue myself and took it to the dealer. They replaced a 30a fuse under the hood and all was well...until I shorted the system again
Need to redo my trailer wiring

* to note this is what they told me, so I hope its accurate.

 

Thanks 14burrito. I have pulled each fuse under the hood and checked it. Maybe I need to pull them all again... Mine all looked good, but maybe one is open but not obvious. I will test each with an ohm meter this time around...

 

Finally solved the issue! I broke down and took the truck to the dealer. After an hour and a half, they came out and told me it wasn't a fuse and something in the wiring. They then offered to replace the "harness" for something just over $300! I decided not to have them do it and took another look at it. I traced the wires back from both connectors to the point where they were spliced together and separated the wires. Sure enough, there was no connection between the main harness and the 4 pin plug. After further investigation I determined the wire break was inside the 4 pin connector. The wires going to the 4 pin connector are pretty small, perhaps 18 ga or so and it appears that when i plugged in my shorted trailer, rather than taking out the fuse, it fused the wire... I went to the internet and found an aftermarket cable / connector for under $30. It fit perfectly electrically, but I had to make a slight modification to the mounting plate to get it to fit in the original position. Everything is now up and running, and the new cable has much beefier wires on the 4 pin connector (~14 ga), so if I plug in a shorted trailer again, I would expect the fuse to blow, not the wire. Here is the link to the assembly I bought. Installation was quick and painless.

http://www.etrailer.com/Custom-Fit-...ndra/2008/HM11143395.html?vehicleid=200815258