Brake Controller Replacement

I suspected this one was about to happen. Since I replaced the brake assemblies at the start of the season, and perhaps even before that, the braking of the Alto just seemed to be a bit off. I first thought the brake shoes needed further adjusting, but that made no difference. The magnets were buzzing, so they were getting power, and given the adjustment attention the shoes were getting, the next possible cause was the controller.

Very early Altos had the option of an onboard proportional brake controller. This unit utilized signal input and power from the 4 way wiring, determined the braking output required, and then sent this along to the brakes. From a manufacturing perspective, it provided an easy turnkey solution, with minimal requirements from the tow vehicle. However, it did not provide any ability for the driver to adjust the controller output, to adapt to varying driving conditions. In fairness though, it performed quite reasonably for the past ten years, but now is the time for a change.

Lots of options for controllers out there, so a little research was in order. As much as the installation convenience of a wireless setup was appealing, I was a bit concerned with the connectivity aspects of that controller. A wired solution, although more work, definitely appealed to me, and offered a much wider variety of choices.

One particular product caught my eye, and that is the Redarc Tow Pro Elite. Redarc is an Australian company, with a long history in design and manufacturing of electronic components for vehicles. They also have a division that specializes in providing these components to the military, and to me, that also shows a mindset towards delivering a high spec, high quality product.

A key feature of their brake controller is they have separated the user input control from the inertia component. This allows the inertia part of the controller to be mounted most anywhere, and a CAT5 cable connects the user input control. As well, it offers both proportional control and complete manual control. I liked the idea of being able to mount the user input control in a spare switch blank, on the left side of the dash, well within easy reach. I read through all their posted information, and decided this was going to be the one.

Once it arrived, the hard part began. The Santa Fe had no under dash trailer wiring for a controller, just the stop/turn/tail connectors in the back quarter panel. This meant running at least one wire back and out to the 7 pin plug. As the recommended place to get the brake signal from is the brake switch itself, above the pedal, this required a little investigative analysis to determine just which wire to tap into.  The key is finding the wire that becomes energized when the pedal is pressed, and has 0 volts through it when not pressed.

What was also needed was uninterrupted fused power from the battery. Connecting to the battery directly was recommended, which was simple, getting through the firewall was another matter. There is not a hell of a lot of space up under the dash, let alone a spot to get a drill into, and a hole safely created.  Any thoughts of feeding the wires through an existing grommet were not to be, as these things were well out of normal reach.

I have come to the conclusion that working on your back, contorting to move your arms around all those bits under the dash, is not a very fun activity, and actually, damn uncomfortable. Gives one a little better appreciation of what mechanics go through on a daily basis, and why it costs so much for their services.

Found a spot to run the wires to the battery, and that part was soon over. Next was feeding the brake output wire to the rear of the Santa Fe. I ended up tucking it behind the side interior trim pieces, prying or removing as I made my way to the rear. I did manage to squeeze the wire through the existing grommet that the  factory trailer connectors used, so that was a bonus. As part of this process, I contemplated running a separate 12 volt line to the rear as well, but given that we have solar, and the somewhat minimal charging value of this line, I decided against it. The 7 pin plug was rewired, and now this part was done.

a few things had to come out...

Part of the marketing for the Redarc is the ability to mount the main part of the controller up and out of the way somewhere under the dash. Have you stuck your head under there lately? Good luck finding even the tiniest piece of real estate to mount this thing. Even though the orientation of the part does not matter, there is just nowhere to put the thing. Perhaps other vehicles would have a spot, but that was not in the cards for me. I ended up mounting it low on a plastic side panel, just by my right leg. It is well out of the way of any possible leg movement, however exaggerated, so that was not a concern. It needed a couple of holes to accommodate the wires, but in the end, so what. Ya gotta do what ya gotta do.

Popped the fuse in, and we were good to go. Initial no trailer testing showed that it was all working as expected. Now on to the Alto modifications.

fits like it was meant to be there

tucked somewhat out of the way

The front electrical cubby was opened to gain access to the existing controller, and the trailer wiring junction box. There are lot of wires in that little box, and to make things worse, one needs to map the wire colours from the 7 wire cable, back the the 7 pin plug on the tow vehicle side. Did I mention they do not all map to the same colour? Once identified, I removed the existing wires to the old controller, and it was then just a matter of putting the previously unused blue brake wire into play. This now meant that the output voltage from the new controller will now flow all the way to the junction box and out to the brakes. I was anxious to give it all a live test.

a bit of a puzzle to solve

The next morning the Alto was hitched up and off we went. The new controller needed a few braking cycles to calibrate itself to its mounting orientation. The LED indicator in the dial is your view of what the controller is thinking, and it was soon glowing a solid blue, telling me it was calibrated and ready for adjustment. To this point there were no error indicators, and that is always a nice treat.

The little dial allows you to adjust the proportional voltage output to suit the weight of the trailer, and the general driving conditions. As the neighbourhood was quite, I just cruised around the streets, each stop sign providing yet another testing result.

blue means proportional mode

red during braking...which makes sense

Now is about the time to say WOW!

What a difference. After only a bit of adjustment to find the sweet spot, the Santa Fe and the Alto were braking as one...and I could feel it in the seat of my pants. I felt a rush of renewed confidence in the performance of our towing setup. I played more with the settings, and could really feel how each adjustment made it all behave. Then I tried some of the cool manual features of the Redarc, and was again very impressed.

During the time I was trying to figure out what to hell was going on with the brakes, and once I narrowed in on the controller, I really wanted to know what it was actually doing. Was there any power being output, just how much was going to the magnets? The existing controller had a little display readout that showed the output voltage, but this was useless to me when I was sitting in the Santa Fe. How do I monitor this?

The solution was to video the controller while underway. I mounted a little compact camera above the display, and when we pulled out, I started the video and off we went. The results were most interesting. Reviewing the footage, it soon became apparent that the output rarely moved above 1 volt. At times I would see 1.4, and maybe a tad higher. A real test was needed to see how high this output would get. On our Syracuse trip, the Green Lake State Park dump station is at the bottom of a good sized hill. I told Dale that I was going to do a couple of panic stops, to try to induce a wheel lockup by the controller. After a couple of these, and seeing that the output voltage only slightly jumped above 2 volts, I confirmed the controller was toast.

The new controller does not tell you the brake output voltages, it just provides you with a control dial and LED feedback. This is plenty good enough to support every day use, but the geek in me wanted to know more. To do this meant a trip to my favourite electronics shop, to pick up a little DC voltage display, and a tiny enclosure to mount it in. This was then wired between the blue brake output wire and the negative ground.

Stuck to the dash within view, every press of the brake instantly showed me the voltages being output to the magnets, and the resulting brake effect I could feel. It also told me just how screwed up the old controller was. I was now routinely seeing a broad range of voltages, anywhere from .5 to up over 6 volts. Based on the weight of the Alto, and the brake feel, the current sweet spot on the adjustment dial is 4, on a scale to 10.

A cool little feature the voltage display showed me was the impact of being stopped while on a hill. Normally, at a level stop, the voltage drops off to zero. I noticed when stopped at either a downwards, or upwards incline, the controller would throw a little voltage to the magnets, to help hold the trailer in place. Sure enough, this was confirmed in their literature. What a great idea. Gotta love the attention to the little details.

On our next trip out, the new controller was awesome. I really could feel how it was participating in the braking effort, and it gave me a good secure feeling.

I know I’m going to appreciate having this nifty controller along for the ride.