When installing a Tow-Pro Liberty into a Toyota 4Runner MY18+, the factory tow package harness includes a diode that lowers the brake light trigger voltage, preventing calibration if using a standard plug-and-play harness like REDARC’s TPH-021.
To resolve this, REDARC recommends splicing the TPH-025 harness directly into the factory trailer brake harness with the specified wire connections, ensuring proper calibration and operation.
REDARC recommends seeking the support of a qualified auto electrician or technician.
Important
For your safety, REDARC recommends installation by a qualified technician. Seek support from a REDARC recommended dealer or installer - Find Your Local Installer
This information is applicable to the following products:
- Tow-Pro Liberty (EBRH-ACCNA)
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
