Ford Focus Trailer Wiring | etrailer Tekonsha T-One Vehicle Wiring Harness Installation - 2015 Ford Focus. Speaker 1: Today on this 2015 Ford Focus, we'll be having a look at and showing you how to install the Tekonsha T1 vehicle wiring harness with a four pole flat trailer connector. 2014 Ford Focus Trailer Wiring | etrailer Lowest Price Trailer Wiring Guarantee. Installation instructions and lifetime expert support on all purchases of 2014 Ford Focus Trailer Wiring. Order online at etrailer or call 800-298-8924.