Brake controller wiring question - help needed


Hi All,
I’ve wired in a REDARC Tow-Pro Elite trailer brake Controller into my 2014 Jeep JKU with the max tow package.
Lights work. Bake lights illuminate. Turn signals work. I assume all of these are working due to the stock four pin connection into the seven pin harness.
The blue light on the control knob light “breathes” blue when I depress the knob. All that said, the brakes are not engaging. I’ve gone through all the wiring and believe it’s all correct. The red wire from the brake controller is connected to the brake light trigger wire in the brake wiring loom just above brake pedal. It’s the white wire with tan stripe per various videos on YouTube. All instructions indicate that the wire should only carry a signal only when the brake pedal is depressed. Here’s the catch, it’s “hot” all the time. So are all the other “hot” wires in this loom. So as a result I’m not getting any actual braking power to the trailer.
I’m stumped. Any advice on what to check or where else to connect the red brake controller wire would be appreciated. I need to tow at 2500lb trailer through the mountains of WV this coming weekend. All paved roads.

Sent from my iPhone using Tapatalk


Well-known member
wait.. stock 4 pin connection? that dont support brakes.. you need 7 pin all the way through for brakes..

I tested mine w/the help of my son and a test light.. had him step on brake pedal and twist the gain back and forth while I watched at the trailer plug in the back, the light come on/off and change in brightness.. If your brake pedal signal is always hot thats not right, the redarc is not registering brake presses? its LED comes on when you push the big pedal.

Tow package didnt come w/a pre-wired brake harness? thats a shame.. I havent had to actually tap into anything in a good while, just make an adapter cable.


Well-known member
Normally the control wire for the brakes is blue.

As Dreadlocks mentioned it is used in a 7 pin.

Recommended books for Overlanding

Long Way Round: Chasing Shadows Across the World
by Ewan McGregor, Charley Boorman
From $14.59
Vehicle-dependent Expedition Guide
by Tom Sheppard
From $119.71
Overlanders' Handbook: Worldwide route and planning guide...
by Chris Scott
From $19.2
Lone Rider: The First British Woman to Motorcycle Around ...
by Elspeth Beard
From $19.95
Cycling the Great Divide: From Canada to Mexico on North ...
by Michael McCoy, venture Cycling Association
From $9.99


To be clear I did wire in a seven pin connector to the rear of the Jeep. Thanks for all the input so far. Helpful.

Sent from my iPhone using Tapatalk

Spanna 53

Don't know about there but here in Aus. The trailer plug is feed off a "breakout " box in one of the rear quarter panels so I take a wire from the trailer plug brake light terminal wire and run it back to the Redarc controller red wire and the blue wire to the trailer brakes 5 volts from memory to apply the brakes so an extra wire in a harness to rear of the vehicle yes it works fine on Hilux just need to get around the Canbus


Well-known member
Hi All,
I’ve wired in a REDARC Tow-Pro Elite trailer brake Controller into my 2014 Jeep JKU with the max tow package. usually has some answers. Try reviewing their installation video.



Well-known member
If the Jeep uses PWM (pulse width modulation) the wires maybe hot (voltage) but there is very little amperage.

Some controllers do not send a signal to the trailer brakes at low speed.


Update- turns out the wire I tapped into is one that only goes “hot” when the brakes are applied. There is a small “plunger” switch on the back of the wiring harness that when depressed cuts the power. When released, it allows for constant power to the harness and hence the wire. When the harness is placed back into the mounting position, the plunger is permanently depressed. I assume that power is then only distributed when the pedal is depressed. I haven’t been able to test this yet. Thanks again for all the suggestions to date.

Sent from my iPhone using Tapatalk


Adventurer, eh?
I don't know about JKs, but when I did a controller on a Journey, the brake pedal used, if I can remember right, ran off of 5v, and may of used a rheostat type system as opposed to an on-off switch. Regardless, it was weird setup and the standard install wanted to tap into a wire by the brake booster to get the signal, which we couldn't find. My plan was to try to impliment a seperate 12v brake switch to the controller but I never got around to it. He sold his entire setup including the Journey.


I have the same controller on my FJ cruiser and had no trouble getting it to work first try, it's an amazing controller and I highly recommend it!

Breathing blue on that controller means it's not seeing the brakes on the trailer, it's what mine does when pressed and the trailer isn't connected. I think you may have an issue with the connection to the trailer brakes as well.