You Should Buy a (Wired) Proportional Trailer Brake Controller!

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Pop quiz!

What’s between you and certain death when you’re slamming the brakes to avoid crashing into the back of a decelerating semi-truck?

Answer: Your brake controller!

You need a brake controller to tow anything with axle brakes, aka, pretty much any RV. You can spend $50 or $400 – and yes, there’s a big difference between the two!

If your tow vehicle did not come equipped with a factory-installed towing package, you’ll need to install an aftermarket brake controller.

I think you should purchase a wired proportional brake controller for the best braking performance and longer brake pad life.

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Table of Contents

A Brief Handshake with Brake Controllers

Never heard of a trailer brake controller before?

A brake controller is a little brain between your tow vehicle and your RV. It triggers the brakes on the camper you are towing.

Tekonsha P3 Brake Controller Mounted Under Dash

When activated, the brake controller sends an electrical signal through your 7-way trailer umbilical cord to the brakes on the RV. By varying the signal, the controller can modulate how much pressure the brakes exert.

More voltage = hard stop. Less voltage = slow stop.

Brake controllers can modulate trailer sway, reduce braking distance, and improve brake life.

There are two basic types of brake controllers:

  1. Time-delayed brake controller: Allows you to select how much power is sent to your brakes over a fixed amount of time.
  2. Proportional brake controller (also known as inertia brake controller): Uses an accelerometer that automatically detects changes in vehicle momentum. A proportional brake controller activates the trailer’s brakes relative to its momentum.

For reasons I’ll explain in a minute, I think you should (most likely) purchase a wired (not wireless!) proportional brake controller.

Do I Need a Trailer Brake Controller?

  • Any trailer with electric brakes must be used in conjunction with a brake controller.
  • Some utility trailers, teardrops, and micro campers under 3,000 lbs may not have any brakes!
  • A few trailers, especially boat trailers and rental trailers, may have hydraulic surge brakes. Surge brakes don’t require a brake controller at all! They are activated by the inertia of the decelerating trailer.

If you’re towing anything with electric brakes, then yes, you need a brake controller. And since almost every RV on the road uses electric brakes, you probably need a brake controller.

If you’re not sure if your RV has electric brakes, just crawl underneath and take a gander at the hubs (behind the wheels). If you see two wires running to the hub, then yes, that hub has an electric brake.

  • Some ancient RVs may have hydraulic drum brakes, but very few of those are still around.
  • Some RVs will have brakes on all wheels. This includes single, double, or triple axles!
  • On the other hand, some RVs only have brakes on the front axle (which may have been legal in the state of the manufacturer, but possibly not in your state!).

Uncle Sam agrees. As you can read in this Trailer Brake Requirements table from RVIA, most states require brakes on trailers weighing 3,000 lbs or more. A few states, like California, New York and North Carolina, are even stricter.

However … your tow vehicle may already come with a factory-installed brake controller!

Most pickup trucks and SUVS with factory-installed towing packages already have an OEM brake controller.

Most factory brake controllers are controlled by the instrument panel or touchscreen on your dashboard.

An aftermarket brake controller, meanwhile, is usually controlled by either an interface on the controller itself or a smartphone app.

What’s the Difference Between a Time-Delay and a Proportional Brake Controller?

So, this question has been well-answered in other corners of the Internet. So I’m not going to spend much time on it.

  • A time-delay controller sends a fixed amount of power to the brakes every time you mash the brake pedal. It’s not a “smart” system. However, you can manually adjust the delay, gain, and ramp-up.
  • A proportional controller varies the amount of braking power based on how hard you brake. The trailer brakes will match yours, essentially. This offers smooth, precise braking performance.

A proportional brake controller uses a device called an accelerometer to detect whether your tow vehicle is speeding up or slowing down.

They both have their place.

  • A time-delay controller is better for off-road applications because you can individually adjust the braking parameters.
  • A proportional controller is better for general towing because it leads to smooth, reliable, on-road braking.

Here’s a graph I mocked up showing the differences in brake pressure response between the two types of controllers.

(These graphs aren’t drawn to scale and will vary depending on brake model and settings, but you get the idea).

RV Trailer Brake Controller Time-Delay and Proportional Brake Response Graph

Most RV owners will be best served with a proportional controller.

We’ve only shaken hands with the technological side of brake controllers. If you want to learn more, I think these other two articles are really helpful.

Why I Think You Should Purchase a Wired Proportional Brake Controller

So, let me be honest.

When you first look at the price tag for a wireless proportional controller, you might barf a little.

  • A run-of-the-mill time-delay brake controller is about $50-$75.
  • A proportional controller is $75-$400.

But it’s still worth it.

  • You’re extending the lifespan of your trailer brakes AND tow vehicle brakes, which can easily pay for the upfront cost of the proportional controller.
  • Proportional controllers excel in different on-road conditions, such as stop-and-go traffic, highway deceleration, driving in the snow, etc.

What’s the Best RV Trailer Brake Controller?

Choosing a brake controller can feel overwhelming.

  • Wired or wireless?
  • Dash or under-dash mounting?
  • Hardwired control knob or smartphone app?
  • 2-axis or 3-axis accelerometer?
  • Compatible with multiplex wiring?
  • Able to adjust braking parameters?

Some models, like the Autowbrake Electric Brake Controller, are mounted completely on your trailer. You don’t install anything inside your tow vehicle at all!

While other models, like the Redarc Tow-Pro Elite brake controller, mount completely inside your tow vehicle. You hardwire them into your dashboard wiring harness.

There is one brake controller that stands above the crowd, though: The Tekonsha Prodigy P3

The Tekonsha P3 is the best-selling trailer brake controller for a reason!

  • Great price point for an electronic proportional brake controller!
  • Automatically levels; mount in any vertical orientation
  • Compatible with up to 4 axles (8 brakes)
  • Displays read-out information on an LCD screen
  • 5 stored brake settings and 3 boost settings
  • Manual override lever
  • Diagnostics and troubleshooting

I’ve installed several P3 controllers myself, and I love them. You can usually install them within 20 minutes.

The one ding against the P3 is that it can become a “kneeknocker” depending where you mount it on your dash.

If you like Amazon, here’s where to buy the Tekonsha P3 on Amazon.

If you prefer to shop elsewhere, my favorite online retailer is Etrailer. You can check out the Tekonsha P3 at Etrailer here.

^That’s not even an affiliate link! I just really like Etrailer.

Other good controllers include:

  • Redarc Tow-Pro Elite
  • Curt Echo Under-Dash
  • Tekonsha Voyager (most affordable!)
  • Psst . . . if you’re reading this content anywhere besides Ask The RV Engineer, it’s been illegally “scraped,” and you’re probably on a spam website. So please be careful! Don’t share any private information, and come back to us at www.askthervengineer.com!

What About the Alternatives?

Vs. Time-Delay Controllers

So, I’m not anti-time-delay controllers at all!

If you go off-roading in your expedition trailer a lot, then maybe you should get one! You can easily customize your braking parameters based on your rig and your road conditions.

If you only bring your RV out of hibernation twice a year, I suppose you won’t harvest the benefits of longer brake life. You might prefer the cost savings of a time-delay controller.

But as the costs of proportional controllers has dropped like a brick in recent years, I think 90 percent of RVers would be best served with one of them.

Vs. Wireless Controllers

Actually, I love wireless controllers. Easy to install, controlled by your phone – what’s not to love?

Unfortunately, they don’t love many RVs. Wireless controllers have an effective range of 20-40 feet. If you can get away with a wireless controller, do it! But most travel trailers and 5th wheels are just too long to be compatible with wireless controllers.

What Happens If I Don’t Use a Brake Controller?

One of two things would happen.

One, your trailer brakes wouldn’t be activated, and your tow vehicle would be responsible for stopping all the weight of your tow vehicle plus RV. That’s a recipe for overheated brakes and fatal collisions.

It’s essential to remember that no tow vehicle is designed with brakes large enough to halt the tow vehicle AND a large RV! A tow vehicle is NOT designed to stop the momentum of both itself and a trailer! A heavy trailer can easily overwhelm a tow vehicle, literally pushing you forward from behind.

Two, the trailer brakes wouldn’t be properly synced with the tow vehicle’s brakes. The trailer would be receiving 100% of braking power all the time. Rather than working in tandem, the tow vehicle’s brakes and the RV’s brakes would be fighting each other. You could jackknife the trailer!

At the very least, you’ll cause excessive premature wear on one set of brakes (or both), which would be expensive to replace.

Ross Recommends:

Hey Reader, I don’t like nettlesome ads any more than you do! So for your convenience, I’ve summarized the products mentioned in this article. Click on these links to shop pricing and availability. I get a small commission at no extra cost to you. Thanks for supporting this blog. Enjoy the weekend!

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Ross

RV engineer by day, intrepid blogger by night (and occasionally weekends). This website is all about how RVs work, and sometimes why they don't. Bookmark pages that you find helpful, and join my email list for exclusive monthly awesomeness.