Installing a 5-Way Flat Trailer Connector on a 2008 Toyota Highlander with Factory 4-Flat Connector

Question:

I purchased a boat with a trailer with surge breaks. My 2008 toyota Highlander is equipped with a 4 pin flat connector but the new trailer requires a 5 pin flat connector in order to turn off the breaks when the car is in reverse. Is there a kit and/or instructions on how to install a 5 pin flat wire connector harness? I contacted U Haul and they suggested contacting Toyota service and they told me to contact U Haul...

asked by: T C

Expert Reply:

You ended up in the right place. The part you are looking for is a 4 Pole to 5 Pole adapter like part # 20036. This adapter will require the least amount of work to install. One end of this adapter will plug into the 4-pin connector on your Toyota Highlander and you will have one more wire to connect. The blue wire from this adapter will splice into the reverse light circuit on your Toyota Highlander.

The surge brake actuator on your trailer likely has a reverse lockout solenoid that is activated by a vehicle's backup lights. Putting the vehicle in reverse allows the solenoid to cut of pressure to the trailer brakes so you can back up without fighting the brakes.

The best place to locate the reverse light circuit on your Highlander will be directly behind the taillight assemblies. When you open the hatch, you should see two or three screws holding the taillight assembly to the vehicle. By removing the screws, you should be able to pull the taillight assembly away from the vehicle. You will see several wires going into different connectors. Locate the wires going into the connector for the reverse light bulb. Using a circuit tester like part # PTW2993, probe the wires to determine which wire has power when the vehicle is in reverse. You can use the included quick splice to make the connection and all that is left is to reinstall the taillight.

expert reply by: John H