One of the first accessories that we added was a trailer brake controller as we tow an aluminum race trailer that transports all of our race gear at https://kasonlauracing.com
The Freightliner chassis comes prewired for the brake controller but the wiring can be hard to find. It's located to the right side of the steering column when facing out the windshield. I ordered the trailer adapter from https://www.amazon.com/gp/product/B06ZZHVZNJ/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 part 3027-P which allowed me to connect my Tekonsha P3 brake controller.
The install was plug and play, I decided to mount the unit under the AC controls on the right side. Out of the way of getting in and out of the driver seat but reachable in case i need to manually apply the brakes.
-Kevin
