Integrated Brake Controller, Hydraulic Brakes and Trailer Wiring for Boat Trailer


I have a 2008 Ford F-250 with an integrated brake controller. I also have a boat trailer with hydraulic brakes. I know the brake controller does not work with hydraulic brakes and I know that I do not really need a brake controller with hydraulic brakes. My question is whether it is a problem having the trailer plugged into the 7 pin socket so the lights will work using a 5 pin to 7 pin adapter when the brake controller is not compatible with the trailer brakes or do I need to do something to disable to integrated electric brake controller.


Expert Reply:

If your boat trailer has a mechanical surge actuator coupler like # 8605001 then no trailer brake controller is required. The inertia of the trailer moving forward provides the compression to push hydraulic fluid to the brakes.

If on the other hand you have an EOH system, electric-over-hydraulic, such as with an actuator like # HBA-12 for drum brakes or # HBA16 for disc brakes, then you DO still need a trailer brake controller to deliver the electrical signals to the actuator, which then converts those signals to hydraulic pressure for the brakes.

Some OEM brake controllers are not compatible with EOH systems. Better aftermarket units like the Prodigy P2 # 90885 and P3 # 90195, as well as some others, DO include an operating mode specifically for EOH actuators. This special operating mode is required since standard electric brakes and EOH actuators present very different electrical loads to brake controllers. Some do not play well with each other.

In terms of the trailer lights all of your trailer lighting signals will still reach the trailer connector on the vehicle. If you have a surge coupler with an electric lockout feature, such as # T4339720, then this will require a reverse light signal from the truck to activate the reverse lockout solenoid that prevents the brakes from engaging when you back up the trailer. In the standard wiring configuration (see photo please) the reverse light signal is carried on the center contact of the 7-way. You can use adapter # HM47570 in the truck's 7-way to give you a 5-pole flat connector option.

If you want to avoid using adapters you can install a 7-way plug and junction box on the trailer, such as # 277-000141. This includes a 7-way plug that can directly join the truck socket and the junction box allows you to easily connect the trailer wiring.

Click to Enlarge
expert reply by:
Adam R

Ask The Experts a Question >>

Products Referenced in This Question

Product Page this Question was Asked From

Similar Expert Q&A Pages

See More Q&A Expert Answers >>