Towing a Boat Trailer Equipped with BrakeRite Electric-Over-Hydraulic-Actuated Disc Brakes  

Question:

Expert Reply:

A trailer that is equipped with an electric-over-hydraulic brake actuator such as the Titan BrakeRite EHB # T4813102 shown in your photos requires that the tow vehicle have a brake controller installed. The brake controller sends braking signals from the tow vehicle to the actuator on the trailer through the 7-way trailer connector. For reference the instructions for the BrakeRite are included. You need to choose a controller that is compatible with an EOH actuator.

Many vehicles with an OEM tow package include an under-dash connector to allow quick plug-in installation of an aftermarket brake controller. In your particular model year vehicle GMC omitted this quick-connect port, however there should be blunt-cut wires under the dash to allow hard-wire installation of a brake controller. I have linked an article that covers the installation process for your Yukon, complete with photo illustrations and wiring instructions.

Among the most popular and reliable brake controllers is the Tekonsha P3, part # 90195. I suggest this proportional-type unit as it is compatible with electric-over-hydraulic actuators and it is easy to set up. The P3 includes a wiring harness with pigtail leads that will splice into the blunt-cut wires under the dash. The wiring scheme is as follows:

GMC Red/Black wire connects to the Black wire on the P3 harness (12V power).
GMC White wire connects to White wire on harness (ground).
GMC Light Blue/White wire connects to Red wire on harness (brake light signal).
GMC Dark Blue wire connects to Blue wire on harness (brake controller output signal).
The orange wire on the vehicle does not connect to the controller.

I suggest you check the power distribution box in the engine compartment to confirm that all fuses and relays required for towing are in place. Any fuse or relay receptacle labeled tow or trailer should have the appropriate fuse or relay in place. The lid of the power box should indicate the fuse values needed.

I also urge you to test your factory 7-way to confirm that all functions are operating before you make your trip to Mississippi. If you have access to another trailer locally you can test the functionality of the wiring in that way, or you can use a circuit tester such as # PTW2992 to test each pin on your Yukon 7-way. The linked article on trailer wiring includes photos of a 7-way with labels for each function as they are typically configured. With a helper in the vehicle to activate the turn signals, lights and brakes you can test the pins one by one to confirm that all the correct signals are present at the 7-way, including the brake control output signal which should be present on the pin at the 5-o-clock position (as viewed from the rear of the vehicle).

As for the trailer itself, before making your return trip confirm that the trailer tires are inflated to the rated pressure as indicated on the sidewall. Trailer tires should always be inflated to their full rated pressure. If your trailer spindles happen to have Bearing Buddies (with a grease zerk fitting) you will want to top off the grease before your return trip. If it has standard grease caps these can be removed to check that there is enough grease in the hubs. Some boat trailers use oil-bath bearings that have an indicator window to allow visual confirmation of oil level. You will also want to check that the trailer breakaway battery is fully charged.

expert reply by: Adam R

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