Reese Brake Controller Wiring Instructions

by Alexis Rohlin

Reese brake controllers are installed on trucks that tow trailers. When towing a trailer, the vehicle and trailer assembly requires a longer stopping distance. The brake controller tells the trailer brakes when to activate and how much pressure is required for the trailer to stop. The electric trailer breaks have a pressure switch that senses when the brake pedal is depressed. The pressure switch works in conjunction with the brake controller to safely stop the trailer. Boats, campers and horse trailers can utilize brake controllers as well.


Examine your vehicle to determine a suitable location to mount the brake controller unit. It needs to installed where you can reach it easily; such a solid surface under the dash, on top of the dash or sitting vertical against it. Double check to make sure that when you drill the holes for the mount screws that nothing will be damaged before you do so.


Put the mounting bracket up against the place you have selected. Hold the mounting bracket straight and place the marker in the screw holes or slots of the bracket to mark on the dash where the holes need to be drilled. Drill 1/8-inch holes though the dash on the marks.


Place the bracket up to the dash, line up the holes or slots on the bracket to the ones you have drilled. Insert the two self-tapping screws into the holes. Tighten them with the screwdriver to secure the mounting bracket. Set the brake control unit onto the mounting bracket. Line up the screw holes on the brake control unit with the holes on the mounting bracket. Insert the remaining two self-tapping screws through the holes and tighten them with the screw driver to secure the unit to the mounting bracket.


Insert the probe of the test light into the stoplight switch, which is located in front of the brake pedal or on top of the brake pedal arm. The stoplight switch will be attached to an electrical connector. Look for the "cold" terminal of the switch, which will not turn the test light on when you press down on the brake pedal. Take a small piece of masking tape and wrap it around the wire so that you can keep track of it.


Disconnect the battery cables from their terminals. Find a location to mount the 20-amp auto-reset circuit breaker as close to the positive battery terminal as you can.


Strip 1/2-inch off the ends of a piece of 12-gauge wire. Insert one end into the wire socket of a crimp type ring terminal connector. Place the wire ring connector assembly into the jaws of a wire crimper and apply even pressure to crimp the wire to the ring connector. Wrap the wire end where it joins the ring and the remaining bare wire with electrical tape. Repeat this process to crimp a ring connector onto the other end of the wire. Insert one ring connector onto the battery side of the circuit breaker. Place the other ring connector end onto the positive battery terminal.


Route one black and one white 12-gauge wire from the brake control unit location through a hole in the dash and over to the battery. If there is no hole for you to use, create one by drilling it. Strip the wires and crimp ring connectors onto one the ends of the black and white wire as above. Attach the ring of the black wire to the auxiliary side of the circuit breaker. Insert the other end of the black wire into a butt connector. Insert the end of the black battery wire that is attached the brake control unit into the other end of the butt connector and crimp the connections.


Connect the white wire ring to the negative battery terminal. Insert the other end of the white wire into a butt connector. Insert the end of the brake control unit's white wire into the other end of the butt connector to connect the two white wires. Crimp the connections to secure them.


Insert one end of the red stoplight brake control wire into the wire tap. Insert the end of the wire attached to the cold side of the stoplight switch that you marked with tape into the wire tap. Snap the wire tap shut to strip the wires and splice them together. If you have a 1989 to 1991 Ford E and F series van or truck with anti-lock brakes, locate the crescent shaped connector in the turn signal harness on the steering column. The cold wire is the one with a light green covering.


Splice the brake control blue brake wire to the trailer brake wire by inserting them into the wire tap connector.


Use plastic cable ties to secure all of the loose wires to the vehicle. Reconnect the battery cables to their terminals.


Test the wire connections. Set the output on the brake control unit to minimum. Attach the blue wire leading from the brake control unit to the test light. Hold the red wire of the test light to the positive battery terminal. The bulb should light up and gradually get brighter and the red output indicator light on the brake control unit will glow brightly. Set the Sync control of the brake control unit to maximum. Touch the positive battery terminal with the red wire and the bulb should light up brightly.

Items you will need

About the Author

Alexis Rohlin is a professional writer for various websites. She has produced works for Red Anvil Publishing and was one of the top 10 finalists in the 2007 Midnight Hour Short Story Contest for Rohlin holds a Bachelor of Fine Arts in English from Madonna University.