Brakes of Trailer Towed By 2011 Nissan Frontier Immediately Lock Up When Trailer Is Plugged In

Question:

I have a 2011 Nissan Frontier. I originally purchased 118525 - T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector and it worked fine. Then I needed to upgrade to a 7 pin plug to provide trailer breaks. I purchased the following: 118267 - Replacement OEM Tow Package Wiring Harness, 7-Way C51110 - Curt Venturer Trailer Brake Controller C51382 - Curt Custom Wiring Adapter Now when I hook up a trailer with brakes, the trailer brakes are constantly locked up. We tested the blue pin on the 7 pin plug and it is constantly getting 13 volts. I unplugged the brake controller and still get 13 volts. Am I missing a relay or anything? Can you help me figure out if I need anything new or if I have a faulty device? Thank you

asked by: Jeff

Expert Reply:

We've been receiving reports that on some vehicles, Nissan cross-wired the wiring harness that the 2-pin portion of the # 118267 plugs into. You can confirm this by using a circuit tester like # PTW2992 and testing the 7-way trailer connector. On the brake output pin, which is in the 5:00 position, you should not have any voltage unless the manual override switch is engaged on the controller. If you test the pin in the 1:00 position, you should show a constant 12-volts. If the function of these two pins is reversed (which is certainly what it sounds like), cut the wires on the 2-pin harness, and swap them, using butt connectors like # DW05745-10 to reattach them.

Instead of cutting and splicing the wires back together, you might be able to disassemble the wires from the plug itself and swap them. Take a look at the technical bulletin I've linked you to.

expert reply by: Mike L