How to Install a REDARC Tow Pro Brake Controller

Steve Cassano — 19 December 2019
We walk you through the step-by-step installation of a REDARC Tow Pro V3 Brake Controller, from positioning to wiring.

Last mag, I wrote about installing an electronic throttle controller to give your vehicle that extra oomph. The iDrive I went with provides smoother, more responsive acceleration and pedal feel, plus it’s small, inexpensive and easy to install. A quality throttle controller is a great addition to any rig, especially if you’re towing.

But what happens when you wish to slow down safely and in a controlled manner with your camper in tow? These days, you’d be hard-pressed to find a contemporary camper that hasn’t done away with the old hydraulic braking system and incorporated electric brakes. Electric brakes are becoming the norm. Even the lightest of campers have electric brakes optionally fitted. 

Of course, if your trailer is fitted with electric brakes, then the tow vehicle will require a brake controller to control the trailer and its handling.


Let me start by busting a myth that keeps on getting circulated by so-called experts in the field of 4WDs and trailers. It’s often stated that if you’re towing over 750 kilograms you legally must have some form of brakes fitted to the trailer. That’s partially true but not fully.  

750kg is not the maximum unbraked threshold for all cars. Some vehicles, for example the latest Suzuki Jimny, may have a maximum towing capacity of 1,300kg, but have an unbraked towing capacity of 350kg, not 750kg. Therefore, vehicles like the Jimny — and I suspect many other light weight vehicles — require trailer brakes even if towing below the 750kg mark.

So it’s best to do your research to find out the vehicle’s legal towing capacities and other weights, such as the GVM and maximum tow ball weight. You may be surprised by what you find.

When it came to my new 4WD, I familiarised myself with its towing limits before choosing a brake controller. My vehicle has a 2,500kg tow capacity, along with max tow ball weight of 250kg and 750kg unbraked limit. 

This article assumes that your vehicle has been fitted with the correct tow hitch and wiring harness for towing, as mine had from factory.


Many newer 4WDs don’t provide much real estate around the dash and surrounds, making it hard to “add” things. My previous brake controller wouldn’t do for my new Jeep; while it worked quite well and was good value, it was too bulky and I just couldn’t figure where I could possibly install it, whilst maintaining easy access and visibility.

It didn’t take me long to come across the array of brake controllers available from REDARC.  There are a couple to choose from but I got the flagship Tow Pro Elite V3 Electric Brake Controller. The brake controller comprises the main body, a remote head, some wiring and instructions. 

It’s the ability to “hide” the main body under the dash (or anywhere stable) and have only the small remote head accessible and showing that makes the REDARC controller so appealing and practical for modern vehicles.

It should be noted that along with the controller, you’ll need a wiring harness to integrate the controller into the vehicle’s existing tow wiring harness.

Fortunately, when it comes to these wiring harnesses, REDARC have made life easy, especially for the more common model 4WDs. Besides a universal wiring kit, there are specific REDARC wiring kits to suit many common models, such as the Ford Ranger, Toyota 200, Prado, Holden Colorado and others. 

These REDARC wiring kits retail for around $290 and supply all that’s needed. They come with a very detailed pictorial set of instructions, that show how to install the kit and even suggest where best to mount the main body and remote head. Depending on which model kit you need, it may even include necessary brackets to make life easier to mount the main body and additional instructions on how to best route the wiring through the cabin.

In my case, the Jeep (always the black sheep) can use the Universal Tow Pro Wiring Kit, which still came with excellent hardware and instructions.

As an important side note: modern vehicles equipped with “CAN Bus”, which is a standard design that allows microcontrollers and devices to communicate with each other (such as with AEB), will require specific diode-incorporated wiring for the trailer brakes to work correctly.  Older style vehicles can do with run-of-the-mill trailer wiring. 


The first consideration for me was to where to install the remote controller and main unit.  While it takes little space and comes with a long lead to reach the main body, I needed to ensure the remote controller was visible and easily accessible. 

While many people suggest having it fitted around the vicinity of the dash, I thought, why not above my head? Up there, it’s easily visible and still quick to access, without your eyes having to stray far from the road. Many vehicles have an array of plastic panels and hidden voids throughout, making this positioning possible. After much deliberation over a beer or two, I found a suitable place with a void behind, above the rear view mirror. 

Using an array of plastic panel removal tools, I prised away the panels to gain access. I couldn’t believe it; it all fitted like a glove and only required a small drilled hole. Perfect! Even though in some cases REDARC optionally supply a bezel for the remote head for a specific spot, you’ll be amazed at the versatility of mounting possibilities when it comes time to fit your brake controller’s remote head.

With the remote head secured, I connected the supplied cable and routed it to where I wished to have the main controller body. Where would that be, exactly? As mentioned, this will be an easy decision to make if you’re lucky enough to have one of the common model vehicles; for these, REDARC have provided great suggestions. 

In my case and with many other vehicles, you’ll need to think carefully. Even though it takes up little room, it needs to be secure and sturdy. Fortunately, though, it can be placed in any orientation.

Removing the glove box will open up opportunities for securing the main body. It really needs to be screwed somewhere, as it cannot be subjected to excessive movement; it needs to be relatively stable in its place for it to function correctly.

I found the space along the left side of the glove box a fine position, which didn’t interfere with the glove box’s operation. After marking the proposed holes, I drilled small pilot holes and then used a couple of self-tapping screws to secure the unit in place. This still allowed me access to the connectors, both front and back of the body. 

Next I connected the end of the cable coming from the remote head, which just clicked into position. So far, so good. Pretty easy thus far!


The next task is to route the two wiring harnesses. With ample wiring for the power lead and trailer harness, it’s just a matter of finding the best route for reaching the battery power and trailer plug respectively. I must add, the wiring was excellently put together and protected with split-tubing and tape, which instilled confidence in REDARC’s quality.

Once all coloured leads (the white earth lead was already connected) were snapped into their respective position and the connector plugged into the main body, I routed the black power lead toward the battery. As you will in many vehicles, I found a rubber grommet that allowed passage between cabin and engine bay. With some ungainly yoga moves and with the aid of a twisted coathanger, I routed the power lead to the battery post. The lead was excessively long, so I trimmed heaps and re-soldered the fuse back in line. Note that fuses should always be as close to the battery as possible.

Next was routing the trailer harness towards the trailer plug. With a little imagination, use of panel-removing tools, and passage through another convenient grommet, I managed to reach the trailer plug with just 25mm to spare. How lucky was that! 

You’ll find about halfway along the harness that REDARC have merged a diode in-line. This diode is to help manage the braking systems, in certain circumstances, with cars fitted with CAN Bus technologies such as AEB. If you’ve got an older model vehicle this is most likely superfluous, but check with the friendly staff at REDARC or Doctor Google if concerned or curious.


Once I was convinced I’d safely routed the trailer harness and ensured it was tucked away with no chance of accidental snagging on errant road debris, I detached the seven-pin trailer plug from its position and undid the cover to reveal the seven wiring positions, all occupied except position five.  

The task at hand now is to two-fold. Firstly, to gain better access to the wires, I carefully stripped about 200mm of insulation from next to the plug, with the aid of sharp snips. Next I passed the blue wire (main communication wire from the brake controller) through the rubber cover, trimmed it to length and tightened it into position five. Don’t overtighten as the screws are small and look “softish”. 

As REDARC suggest, I undid the red wire (that controls the vehicle’s stop lights) from the trailer plug and cut off about 150mm and discarded this bit.

After shedding 100mm of insulation for access and with the aid of a crimping tool, I used the supplied butt splice and joined the just-cut red wire to the red/white wire from REDARC’s harness, then used the supplied heat shrink to protect my work. 

Next I attached the remaining red wire from the REDARC harness to pin six on the trailer socket. A little wire trimming was need to ensure all wires were equal length.

Now on the home run, I wrapped all wiring with a combination of split-conduit and electrical tape, and tucked it all in place with cable ties and placed the plug back in position.


The overall job is straightforward and doesn’t really need any special tools or skills. With a little imagination and time (it took me three hours), and following REDARC’s easy instructions, you’ll easily knock it over in an afternoon, especially if you have a more common vehicle; REDARC’s suggested routing and steps will save you time and brain power. 

Like all of REDARC’s products I found the Tow Pro Elite V3 Electric Brake Controller and Wiring kit to be excellent. Happy wheeling. 


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