bing tracking image
Q & A Icon

Locating Blue Wire On Motorhome When Installing Brake Controller


I have a 2007 34 ft. hurricane and trying to install the brake controller. I purchase the adapter and controller from you guys. I finally found the connector under the dash after 1 day of crawling around. I can not find the blue wire for the life of me in the rear of the motorhome to connect into the 7 pin. The motorhome had the 7 pin on there and I have trace back to where the factory harness tees off but do not see and solid blue wire for the electric brakes


Expert Reply:

Larger motor homes typically do not come with the brake controller wiring installed. The first step I would take is to make sure that the connector you found on the motor home under the dash is indeed for a brake controller. If the connector on the motor home matches the connector you purchased, then you should be able to plug in the harness and test the pins for the black and the red wires using a circuit tester like part # 40376. The black wire should show 12 volt power all the time, and the red wire should only show power when the brake pedal is pressed. I have attached a photo of the harness which shows arrows pointing to the location of the pins for the red and black wire.

If those two functions check out then the next step would be to plug in the brake controller. With a helper in the drivers seat, have them hold the manual override on the brake controller while you test the pin in the five oclock position on the 7-way trailer connector (see photo).

If there is no power at the trailer connector, then it may be possible that the wiring harness you found is not connected to the 7-way connector on the back of your 34 ft Hurricane motor home.

The next thing you will want to do is to visually inspect the 7-way connector at the rear of your motor home. You will want to see if there are 7 wires attached to the back of the connector, and if there are, then determine what color wire is attached to the pin in the 5 oclock position per the photo I have attached. It may be possible this wire is not blue.

If there is no wire on the 7-way connector, you would run a wire from the 5 oclock position on the connector up to the back of the brake controller. You would cut the blue wire coming out of the # 3035-P harness on the back of the controller and connect the wire from the controller to the wire you just ran from the connector at the rear. This would bypass the vehicle wiring harness connection and be hardwired from the brake controller output to the 7-way on the rear of your motorhome. Simply tape off the other end of the blue wire that you just cut that is running to the harness you connected under your dash.

click to enlarge
click to enlarge
expert reply by:
Jeffrey L

Products Referenced in This Question

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>