Troubleshooting Brake Controller that Blows Fuses When Connected

Question:

I have a 2005 Electronic brake control for 2, 4, 6, and 8 brake applications. I have not needed or used it for about 15 months, but it worked well the last time it was used. Recently, when I hooked up my trailer, I noticed that the red brake controller lights were not working. I drove the rig very carefully using the tow vehicles brakes, later I found that the 20A fuse for the controller was blown. After checking for broken/grounded wires, and finding none, inspected the plug-in socket and wiring carefully, I have replaced this fuse several times, only to see it blown when the brake pedal is depressed. This is happening with the trailer plug disconnected. With a good fuse installed, the controller messages are oL and SH, which I am told means overload, and short circuit. I have removed the controller plug, checked the pins for corrosion, and done the same for the trailer plug socket, all of these are in very good shape, as is the rest of the 2007 Honda Ridgelines vehicles wiring. my sense is that there must be a shorted connection, but I have been unable to find any. Can these error messages mean that the controller is bad? Is It possible to test the controller separately? In desperation, I have bough a new controller, but I will not install it until I am sure that there is no wiring defect. Can you help?

asked by: Claude W

Expert Reply:

The Prodigy brake controller you have has different amperage requirements for protecting it based on number brake assemblies used. If single or tandem axle you need 20 amp protection or if triple or quad axle you need 30 amp.

You might double-check the wiring of the brake controller and then also the condition of the trailer wiring connector at the rear of the vehicle as well as the wiring? A short here or corrosion is also a very likely candidate and is almost always the problem when an issue pops up after months of non-use.

expert reply by: Jameson C