In which your narrator is flummoxed by a bit of electronics.
So, I’m a firm believer in “Trust but Verify”, so I wanted to be sure that I knew which wires in the trailer wire were carrying which signals to the junction box*. Because I can’t be both in the drivers seat of the Honda and sitting at the trailer tongue with a multimeter, I enlisted the help of the youngest offspring.
He loved sitting in the drivers seat, stepping on pedals, flipping levers and things were going pretty well.
I was able to confirm my ground, hot, turn signals & marker lights. That left two terminals unaccounted for and no trigger voltage for the trailer brakes. No matter how hard he stepped on the pedal or pressed the override button, I wasn’t getting voltage on either post, but I was starting to get pretty hot under the collar.
Time to pull the dashboard apart again and make sure that everything was working correctly. There’s only four wires between the controller and the Honda, so it shouldn’t be too hard to sort.
Pin 1, Constant 12V in, check.
Pin 2, Solid ground, check.
Pin 3, nothing, nada, zip, zilch
Pin 4, 12v in when I press the brake pedal
Process of elimination tells me that Pin 3 is supposed to be sending voltage back to the trailer brakes.
Time to reach out to tech support on an out of warranty trailer brake controller.
Yup. Just installed. Out of warranty. As big as Fessick was, combined with the fact that the utility trailer doesn’t have brakes (yet), I never installed the controller. The two year warranty expired over a year ago. Time to reach out to RedArc and see if they’re willing to help. I’m prepared to buy a new one if necessary, but I’d rather not.
Their Australian based tech support works day shift in Australia, they start at 4:30 p.m. Eastern time, which is great for them. In all seriousness, it shows that the company has some respect for their employees.
Any way, I type up an email, describing my install and how things were working, or not working and cross any fingers.,
The next morning I wake up to find a very detailed message explaining that the Tow-Pro Liberty is smarter than I am. Apparently the little red box checks the wiring when it powers up and if it doesn’t detect an inductive load, it won’t put out any voltage. And multimeters aren’t inductive loads. The message includes instructions on wiring up a light bulb and a link to a video showing how to test the Liberty with an incandescent (NOT LED) test light.
Do you know how hard it is to find a non-LED test light in 2025?
Luckily, they aren’t expensive ($5), just hard to find.
Two days waiting for Amazon to deliver the test light and I reinstall the controller. Clip the alligator clip to a scratch awl & jam that into the ground contact. Jam the test light pin into the brake contact. Now to press the manual override button on the dash & see if the light hanging from my back bumper lights up.
…..Cue the sad trombone. Button on dash, light on rear bumper. The boy child is camping with the scouts for the weekend, and the girl child has a gaggle of girlfriends over.
Modern problems call for modern solutions, as a wise man once said.
Put my phone on the ground under the bumper and activate the camera remote app on my watch. Now I can see the light while I’m in the driver’s seat.
GREAT SUCCESS
The light lights up. The brightness of the light is controlled by the gain on the controller.
When the boy comes home tomorrow, we’ll plug the trailer into the truck and see which terminal is getting voltage when I step on the brakes.
*Turns out that the brake controller is powering the blue wire, terminal 7 in the junction box, which is exactly how it should be. My obsessive need to be certain, caused me several days of delay.
Modern Anachronist 