Can Towing and Flat Towing Harness be Combined on 2018 Ford Focus?

Question:

We purchased a 2018 Ford Focus Hatchback to be used as a Dinghy behind our motorhome most of the time but would also like to add a hitch receiver and a trailer towing lighting harness on the occasion that we wish to tow our small utility trailer. Your site recommends the Curt hitch # C11158. Your site also recommends the Tekonsha T-one vehicle wiring harness with 4 wire flat connector for the trailer wiring #118674. Your site also recommends the Roadmaster High Power Diode wiring kit RM-154 as one of the towed vehicle lighting wiring options. Can this towed vehicle wiring harness be combined with the Tekonsha #118674 trailer wiring harness so that I may have both towed vehicle as well as trailer towing capabilities on the Ford Focus? I was looking at the possibility of ing the diodes from the RM-154 between the plug in connector on the #118674 and its control boxes, lengthening wiring as necessary, thus not having to cut into the vehicles wiring system. Without having the two systems available myself it is impossible to know if the system will work properly combining the two

asked by: Sherman F

Expert Reply:

No, you would not be able to somehow combine the two wiring harnesses to use with your 2018 Ford Focus, they are for separate applications and need to be treated as such. Wiring Harness # 118674 will be what you need to install for a 4-flat to tow with hitch # C11158 and Roadmaster Wiring Kit # RM-154 should be installed for flat towing, but there cannot and should not be a combination of the two.

expert reply by: Kyle S