Troubleshooting Unconnected 7 Wire Harness Strand and Brake Controller

Question:

Found this wrapped up. It’s hot. This is where it leads to. I have a perfectly working plug. Strange.

asked by: Nathan V

Expert Reply:

Unfortunately your photo did not come through. I'm a little confused by the description...do you have a working 7 way trailer connector at the bumper and additional wires? If so, this may have been the wiring for a second 7-way for the bed of the truck like # 50-97-410. That would not be an issue with your brake controller not working unless the disconnected harness was defective and shorted your system. I recommend you use a circuit tester like # PTW2993 instead of a multimeter to test each wire function. I've attached a wiring article to assist so you know the pin functions and locations to assist.

I've also attached a brake controller troubleshooting and wiring article to help you troubleshoot.

expert reply by: Jason S

click to enlarge

Nathan

4/13/2018

Found this wrapped up. It’s hot. This is where it leads to. I have a perfectly working plug. Strange.

Jason S.

4/13/2018

Thanks for emailing the photos. I've linked them to assist. It does appear that it was for a 5th wheel trailer or a truck bed camper and they either installed a 2nd 7-way at some point and cut off the end or they had it hard wired all the way back to that connection and just cut it when they were done. I'm glad you found it as hot wires could cause issues when not taken care of. If I were you, I'd use the Hopkins Endurance 7-Way # HM48480 to add a 7-way to the bed of the truck since you already have all the wiring that works. I'd mount it just like the # 50-97-410 for 5th wheel and gooseneck trailer connection. If you don't want he extra connection, you can simply remove it at the connection you pictured.