Power Wire on T-One Wiring Harness # 118520 Needs to be Connected to Battery on 2009 Mazda CX-9

Question:

Ive read that the power wire to the battery is not necessary if you dont need to power trailer brakes. Is that true? I only need to connect trailer lights. Can I get away with not installing the battery power wire? If I do need to install the battery power wire, how do I fish it through the car to get to the battery?

asked by: Mike

Expert Reply:

The T-One Vehicle Wiring Harness with 4 Pole Trailer Connector, # 118520, requires a direct connection to the battery. This connection provides the power to the trailer lights while the other connections provide only the signals. This will protect your vehicles sensitive wiring. Without the connection to the battery, the trailer lights will not work. This harness has a 4-Way connector which only provides the trailer with right/left turn signals, brake lights, and running lights.

To connect the converter box to the vehicle battery on your 2009 Mazda CX-9, the easiest thing to do is connect one end of the included black wire to the power wire on the converter. Route it under the vehicle, avoiding areas that might pinch or burn the wire, to the front of the vehicle and up through the engine compartment near the battery. Disconnect the battery before going any further. Next, cut the loop on the yellow wire/fuse holder with the fuse out. Connect the black wire to one end of the yellow wire. Connect the other end of the yellow wire to the positive battery terminal. Insert the fuse and reconnect the battery. I have included a link to the installation details for this wiring harness below.

expert reply by: Michael H