Brake Controller Recommendation for a Truck with Air Brakes and a Trailer with Electric Brakes
Updated 04/28/2025 | Published 08/25/2012
Products Featured in This Question
Question:
I just purchased a 33 gvw truck with air brakes. I thought I could simply plug in to the 7 point connector to the back of truck and connect to the trailer. The trailer has all the dot safety and break away controls on it. I was told that the truck needs a converter from air to electric. Seems strange since I have electric for lights.
asked by: Mike L
Expert Reply:
The trailer brakes work on a separate circuit than the lights. You have a couple of options to control the electric brakes on the trailer.
One option is to use an air over electric brake control, # HA100400C. This unit connects to the air brakes on the truck and when the brakes are applied it sends an electric signal back to the trailer brakes.
The other option, and what I would do, is to use an electric brake controller like # 90885. For either of these controllers, the red wire attaches to the cold side of the brake switch or any dedicated brake light circuit, like the center high mount stop light (CHMSL). It must connect to a wire that only shows power when the brake is pressed and not also when the turn signals or running lights are on.
The black wire connects to the positive battery terminal on the vehicle via a 20 amp circuit breaker # PK54520 for 2 to 4 brakes or a 30 amp circuit breaker # PK54530 for 6 to 8 brakes.
The blue wire will connect to the back of the 7-Way in the 7:00 position. On # 90885, the white wire grounds to the negative battery terminal. I have included a link to the isntallation details for 90885.
Lee
4/8/2025
I want to buy an H100400C When I search that number it comes up as a pencil hitch. Please help me find the controller
Product Page this Question was Asked From
Hydrastar Electric Over Hydraulic Actuator for Drum Brakes - 1,000 psi
- Brake Actuator
- Electric-Hydraulic Brake Actuator
- Boat Trailer
- Travel Trailer
- Drum Brakes
- Hydrastar
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Brake Controller
- Shop: Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Shop: Trailer Wiring
- Q&A: Does the Curt Base Plate Kit Work w/ the Ford Modular Bumper on a 2025 Ford Bronco Everglade?
- Shop: Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Shop: Trailer Hitch
- Search Results: air to electric trailer brake controller
- Search Results: brake controller
- Shop: Tekonsha Prodigy RF Wireless Brake Controller - Trailer Mount w Remote - 1 to 3 Axles - Proportional
- Shop: Vehicle Tow Bar Wiring
- Search Results: ha100400c
- Search Results: trailer brake controller
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Shop: Vehicle Tow Bar Brake System
- Shop: Base Plate for Tow Bar
- Search Results: snowmobile trailer parts
- Search Results: trailer tires and wheels
- Q&A: Towing a Trailer with Electric Brakes with a Semi Tractor with Air Brakes
- Shop: Gooseneck to 5th Wheel Trailer Coupler Adapter - Round - 30K
- Shop: Redarc Tow-Pro Liberty Brake Controller w/ Universal Wiring Harness - Dash Knob - Proportional
- Shop: InfiniteRule Hitch Locks for B&W Tow & Stow and Tow & Stow Pintle - 2.5" Receiver
- Shop: Gooseneck Hitch
- Article: Brake Controller Installation: Starting from Scratch
- Search Results: 100400c
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Video: Tekonsha Prodigy RF Wireless Brake Controller Spec Review
- Q&A: Can 2024 Ford Bronco Be Towed On A Car Dolly?
- Article: Towing a Trailer? Let's Talk About Brake Controllers
- Q&A: Recommended Flat Towing Set Up for a 2025 Ford Bronco w/ the Ford Performance Heavy Duty Bumper
on Brake Actuator
John S.
7/13/2024
90885 brake controller will not operate trailer brakes properly. Those brake controllers look for truck nose to dip to operate the proportional brake control which larger (with air brakes) truck do not do. Only an air over electric brake controller will operate brake properly, like the HA100400C