Why Does Brake Controller Output Circuit of Curt 7-Way # C57674 Light Dimly w Controller Installed

Question:

I just installed the Curt 57674 7-way adapter with test lights, the Tekonsha 118349 Taillight Converter Harness, and a Hopkins 47295 Agility Brake Controller on my 1998 Jeep Grand Cherokee. Installation was a breeze, and honestly it would be hard to mess it up unless you were not paying attention to what you were doing. There was a coiled-up Blue wire labeled Brake Controller up under the dash near the drivers side kick-panel, but I did not use it as I could not figure out where it ties in to the rear of the vehicle. I powered the Brake controller directly from a 20-amp circuit-breaker, and ran my own Blue wire from the controller to the rear of the vehicle. My issue is, aside from the 12V LED on the 7-way adapter being on all the time this I understand, as I wired it directly to the battery via a 40-amp circuit-breaker, the LED for the BK brake connection is on very dim all the time, and the little LED on my Agility Brake Controller the one that tells you that a trailer is connected is on all the time, even though I do not have anything connected. If I disconnect the 4-wire connector at the back of the Brake Controller, the BK LED goes out. Is this normal? or did I possibly wire something incorrectly? I am usually very careful and thorough when I am wiring any accessories, as to where I run the wiring and how I make the connections.

asked by: Alan H

Helpful Expert Reply:

You did everything correctly. Brake controllers are designed to put a very small amount of voltage on the output current at all times as a way to "look" for a trailer connection. When they sense a load on the circuit (the brake magnets in the assemblies) the controller determines that there is a trailer connected.

So what is happening in your situation is that the circuit tester of your 7-way is providing that small amperage load with the circuit tester light on it. That's why the light is barely lighting up. Everything is working properly but basically the 7-way is going to always give you a false reading on whether or not a controller is connected.

When you unplug the 4-way the ground is removed for the circuit tester so it stops working.

expert reply by: Jameson C