How to fit Tow-Pro Liberty in Toyota 4Runner MY18+ vehicles
When it comes to installing the REDARC Tow-Pro Liberty in to a Toyota 4Runner MY18+ vehicle, it's good to be aware that these vehicles feature a diode within the factory tow package harness which is designed to eliminate any positive back feed being applied to the vehicle brake light.
This diode, if connected with an aftermarket plug and play vehicle specific brake controller harness, such as REDARC’s TPH-021 universal wiring harness, causes the brake light trigger voltage to be lower than the voltage at the Tow-Pro Liberty battery input (BLACK wire) by 1.5v or more which will result in the Tow-Pro Liberty not calibrating.
To combat this issue, REDARC recommends you splice the TPH-025 together with the Toyota 4Runner factory fitted trailer brake harness with the following connections.
Toyota: Yellow Connects with REDARC: Blue
Toyota: White/Black Connects with REDARC: White
Toyota: Green/Yellow Connects with REDARC: Red
Toyota: Green Is not used!
Toyota: Black Connects with REDARC: Black