Troubleshooting Trailer Brakes that Lock Up When Brake Pedal is Touched
Question:
When I use the tow vehicle to break as soon as I am on the break peddle the trailer break seems to lock in Can I just use my trailer break control to stop
asked by: Wayne B
Expert Reply:
If you have a brake controller installed in your truck try lowering the gain to see if that brings the braking action down to something manageable when you apply the brakes.
The next thing I would check would be the voltage coming out of the brake output circuit on the 7-way of your tow vehicle. I would use a multimeter like our # PT89ZR to test for voltage on this circuit when you have the brakes applied on a low setting. You should see a number that is much less than 12 volts as 12 volts that should be the max output of the brake controller.
If you see 12 volts there then you know something is not wired up right on the vehicle side of the equation. You will want to sever the brake output wire from the back of your brake controller (typically blue) and repeat the same test with the multimeter. If you get the same full 12 volts with the brake controller set at a low setting then you know the problem is in the brake controller. If you see a lower voltage then the problem is somewhere between the trailer connector and the brake controller. I would recommend you test the wiring from where you severed the wire back to the trailer connector to find the problem and then fix as necessary.
There may be an issue on the wiring of the 7-way, the connector could either be mis-wired so that the brake light circuit is on the brake controller output, or the circuits could be shorting to each other and the 12 volts are being sent down the brake output circuit as well. There also could be corrosion in the plug that could cause these problems. If so, clean as necessary.
I attached an FAQ on trailer wiring for you to check out also.
Products Referenced in This Question
Digital Multimeter with 42" Long Test Leads - LED Display
- Electrical Tools
- Testers
- Multimeter
- Yellow
- Performance Tool
more information >
Product Page this Question was Asked From
Adapter 4-Pole to 7-Pole and 4-Pole
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 4 Flat
- Plug and Lead
- 4 Flat
- 7 Round - Blade
- Hopkins
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: AxleTek Brake Assembly Recommendation for 8k Axles with 4 Bolt Mounting Pattern
- Article: Trailer Wiring Diagrams
- Q&A: Installing a Brake Controller and a 7-Way Trailer Connector on a 2005 Ford F-150 With Factory 4-Way
- Q&A: How to Add Tension to Solera Slide-Topper
- Q&A: Slide Topper Recommendation for Box Width of 90.5 Inches on Gulf Stream Vintage 23BHS
- Q&A: Replacement 7-Way Wiring Harness for 2005 Ford F-150 with Factory Tow Package
- Article: How to Choose the Right Trailer Hitch Class
- Article: Trailer Tire Sizing
- Q&A: What is the Fuse Rating and Power Wire Gauge Used for Trailer Wiring Harness # 118571
- Q&A: Does BOLT Trailer Hitch Receiver Lock For GM Center Cut Key Fit 2021 Chevy Silverado
- Article: Brake Controller Installation: Starting from Scratch
- Article: Best Bike Racks for Electric Bikes
- Article: RV Propane Troubleshooting | Common Propane Issues and How to Solve Them