How to Activate Trailer Tow Charge Circuit in 2017 Ford F-250

Updated 10/16/2018 | Published 10/14/2018

Question:

I see from a previous post that there should a fuse in 27 and a relay in 37, my truck does not have either nor does it have any pins in the fuse box for the fuse or relay. Shouldn’t that be installed already when it has a towing package and the trailer brake control system?

asked by: Kevin D

Expert Reply:

All 2017 F-Super Duty vehicles equipped with a factory trailer brake controller (TBC) utilize a trailer module (TRM) which initiates the trailer charging system.

For trailer charging to operate, the TRM must detect a trailer is connected and a brake pedal input before charging will be present at the trailer connector.

Adding the trailer battery charge relay and fuse into the battery junction box are NOT required to operate trailer charging with a TRM. This is covered in Ford document SSM 46257.

expert reply by: Adam R