Installing a Brake Controller and 7-Way on a Vehicle that has Air Brakes

Question:

Hello, I am trying to hookup a 4 wire Truck with air Brakes to a 7 way flat trailer with electric brakes. I have seen the 1300-80 brake controller option along with the 90885 electric brake controller option, but it seems that these are good options for a 7 wire system. Is there a way to convert from my 4 wire system with air brakes and end up, on the back of the truck, with a 7 way flat socket so I can hook up the 7 way flat pug on the trailer with electric brakes?

asked by: Tyler

Expert Reply:

There is no brake output circuit on a 4-Way to activate electric trailer brakes so you would have to install a 7-Way on the tow vehicle. To do this I recommend # ETBC7. With it you will plug in the 4-Way to get the lighting functions for the trailer and then the remaining connections will be hardwired including the electric brake circuit. I have included links that show and explain the ETBC7 installation.

One thing to look for though is the brake controller red wire connection. Many vehicles with air brakes do not have a brake switch wire that the brake controller red wire can attach to. This means that you will need to find a dedicated brake light only circuit somewhere else. If the vehicle has a stop light or CHMSL fuse and that is the only circuit on that fuse then you can tap in at the fuse.

For a brake controller I do recommend # 90885 because it is easy to set up and use and it is reliable, but for this specific application there is the Hayes Air Actuated Trailer Brake Controller # HA100400C specifically designed for this. This controller uses the air pressure as well as the brake light switch to ensure function.

expert reply by: Michael H