Most vehicles hauling trailers must be wired for electric brakes.
Wiring a vehicle for electric brakes is imperative when hauling a trailer that's equipped with electric brakes. Electric brakes are actuated by an incremental ongoing developed by a committed gadget, customarily fitted in the cab of the tow vehicle, called a brake controller. The controller is activated by the depression of the brake pedal. It then senses the intensity of the tow vehicle's deceleration, and transfers that information through a seven-pin hitch to electromagnets in the trailers brake hubs, which in turn deploy the trailer brakes at the same intensity as the tow vehicle's brakes.
Instructions
1. Locate the tow connection harness of your vehicle. This will be a flat four-pin or a round seven-pin connector fitted near the center of the vehicle's rear if a tow package is installed, and a "dead tail" multi-conductor wire left by the manufacturer beneath the vehicle. Dead tails can typically be found toward the rear of the vehicle or under the driver's door, held to a frame rail by zip ties. Attach the seven color-coded wires emerging from your new spiral-wrapped harness to the seven connections in the terminal hub. Terminal one attaches to a fused black or red 12-volt hot wire from the tow vehicle's battery; terminal two attaches to a green wire from the tow vehicle's right turn circuit; terminal three attaches to the blue wire from your new brake control; terminal four attaches to a white wire to the tow vehicle's ground; terminal five attaches to a yellow wire from the tow vehicle's left turn circuit; terminal six attaches to a brown wire from the tow vehicle's sidelight circuit, terminal seven attaches to a purple wire from the tow vehicle's backup light wire.8. Calibrate the brake controller by following the instructions on its packaging.
The color codes are green for right turn and brake, yellow for left turn and brake, brown for taillights and license plate illuminator and white for ground. Ensure your vehicle's handbook confirms this color code.
3. Fit a seven-pin connector to the rear of the tow vehicle. These universally sized connectors are typically sold in a kit that includes a bracket that attaches with nut/bolt/washer assemblies to the underside of a frame extender.
4. Fit a brake controller in the cab of the tow vehicle. These devices are typically sold with a "C"-shaped bracket, and must be fitted within the driver's easy access when driving, in line with the front/rear axis of the vehicle and within 30 degrees of horizontal. The brake controller will have four wires that operate the trailer's electric brakes and 12-volt hot supply, along with a brake connection and a ground. The color codes are blue to brakes, black from battery hot via an inline fuse, red to the brake pedal microswitch and white to ground. Ensure the manufacturer's instructions confirm this color code.
5. Extend the dead tail or four-pin feed if necessary so that the wires reach the seven-pin connector without being strained.
6. Connect the four wires at the brake controller to their respective mates. Run the blue brake actuator wire to the seven-pin connector. Harness the wires to the seven-pin connector along their entire length in spiral wrap, and use plastic zip ties to fix the harness where it cannot contact hot or moving parts.
7. If necessary, contact your vehicle's manufacturer to learn where they typically tie off the wire.2. The dead tail or a flat four-pin connector will typically be made up of four wires, which operate the trailer's tail, signaling and braking lights.
