How Does a Brake Controller Know when a Trailer is Connected
Question:
Good morning, question is what signal is the brake controller receiving when trailer plug 7 wire is plugged into the vehicle
asked by: Marv
Helpful Expert Reply:
When a trailer with electric brakes is connected to a vehicle that has a brake controller that brake controller is sensing the draw of the brake magnets by sending back a small amount of voltage on the blue wire.
The brake controller also get's signals from the tow vehicle to let it know when you are stepping on the brake pedal. On most vehicles this connection is made either at the brake switch above the brake pedal or through some kind of tow package wiring.
I have included a link to our help article on brake controllers for you. It covers proportional and time delay controllers. If you are in a market for a controller I recommend a time delay such as the P2, # 90885. Proportional controllers activate the trailer brakes in proportion to how much the vehicle is braking using internal sensors. This is the safest way to stop and it reduces wear and tear on the vehicle and trailer.
Jim W.
3/29/2020
I have a Hopkins Agility Brake Controller about 2 years old. The controller worked up to about a month ago indicating the trailer was connected. The red lamp that indicates this stoped working. The controller has voltage and ground from the battery and receiving voltage from the brake peddle. Blue wire good from the controller to the battery connections that stops a brake away trailer. Would one magnet cause the indicator to disappear or the brakes on the trailer to stop working?
Products Referenced in This Question
Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Electric over Hydraulic
- Automatic Leveling
- Under-Dash Box
- Dash Mount
- Up to 4 Axles
- LED Display
- Up to 360 Degrees
- Tekonsha
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Alice
5/2/2024
I have no brake lights with no trailer connected, how can I fix that