Ask a Mechanic: Tow capable doesn’t mean tow ready

Dear Ask a Mechanic,

After years enjoying tent camping, we’ve just bought a used camper trailer and will be towing it with our 2021 Kia Telluride. The trailer weighs about 3,300 lbs (1,497 kg). Although the dealership sells a hitch and the wiring harness that the trailer plugs into, we apparently still need to buy a controller for the trailer’s brakes. Despite advertising a 5,000 lbs (2,268 kg) towing capacity, Kia doesn’t include or even offer one. Is this typical? What’s the best kind to get? – Trailer tugging

Congratulations, and welcome to the world of glamping. We made a similar upgrade in our campsite accommodations a few years ago and wouldn’t look back.

The brake controller situation is one that’s puzzled me for a good while. Although boat and rental leisure trailers often use mechanically operated surge brakes, those for personal-use trailers, like campers, use actuated brakes that require a controller.

Most full-size trucks and SUVs are available from the factory with built-in trailer brake controllers, and have been for years, but many mid-size crossovers, minivans and pickups rated to tow trailers don’t. You’ll have to use an aftermarket one instead.

There are two primary types, time and proportional. Timed are the most affordable. They apply the trailer’s brakes at an increasing level whenever the vehicle towing it also brakes. While entirely functional, they don’t react to how hard the tow vehicle is slowing. Proportional systems use accelerometers to sense how quickly the tow vehicle is braking and will apply the trailer brakes accordingly. This is my personal preference, because, in a panic stop, I want the trailer to do as much of its share of the braking as possible.

Next you need determine the physical type of controller you want. Traditional controllers are unsightly, knee-bashing boxes that are typically mounted under the dash or in a cubby bin. Finding space for them in modern interiors can be challenging.

Wirelessly operated models that don’t require the mounting of visible controllers are also available. Curt’s Echo uses a phone app to set up and adjust, while Tekonsha’s trailer-mounted Prodigy RF includes a 12V socket-powered hand-held controller.

I like having a physical control for quickly adjusting or applying the brakes as needed, just not the ugly box and bracket. Systems where the knobs are handy while the main electronics stay hidden are available. I chose Redarc’s discrete Tow-Pro Elite for my vehicle. Curt, Tekonsha and other companies offer similar products. For safety, professional installation is suggested.

Ask a Mechanic is written by Brian Early, a Red Seal-certified automotive technician. You can send your questions to wheels@thestar.ca. These answers are for informational purposes only. Please consult a certified mechanic before having any work done to your vehicle.