Parts Needed to Add 7-Way to 2005 Ford E350 With 4-Way For Brake Controller

Updated 11/14/2022 | Published 11/12/2022

Question:

Hi! I have a 2005 E350 with the factory 4-pin harness. I found the brake controller plug under the dash on the driver side, but the harness under the vehicle is only four pins and terminates in a square connector almost looks like a deutsch connector. What do I need to upgrade from the 4-pin harness to a 7-pin setup? Are there any drop-in replacement options? Where would I plug-in the additional three wires?

asked by: Eric A

Expert Reply:

So to upgrade from the factory 4-way on your 2005 Ford E350 to a 7-way, all you need is an adapter and some added 10 gauge wire. At the back of your van, along the inside of the driver's side frame rail, between the bumper and the rear wheel there will be connectors with wires run that are power and brake signal wiring. I have added a link below to a help article which shows this. You would also need to run the proper length of 10 gauge wire from the brake controller to the 7-way, so you'd need the following:

- Adapter 4-Pole to 7-Pole and 4-Pole # 37185

- 10 Gauge Primary Wire - Blue - per Foot # 10-1-1

expert reply by: Kyle S