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When you’re towing, it’s not enough to know that your braking system is trying to work—you need to know it actually is. The Roadmaster Stop Light Switch Kit wires directly into the towed car’s fuse box and activates your RV’s monitoring system whenever the brake pedal is pressed. Because it reads pedal movement itself instead of air cylinder motion, you’ll always have a true signal that the brakes are being applied, not just that the system is active. That means less guesswork and more confidence every time you stop.
An improperly aligned braking system can keep pressure on the pedal even after you stop, leading to tire wear or brake overheating. This kit helps you catch that problem before it causes harm by sending a signal whenever the brake pedal is actually depressed. You’ll know right away if the brake is being applied when it shouldn’t be, protecting your vehicle’s tires and braking components from costly damage.
Some vehicles disable their OEM brake light switch when the ignition is off or in tow mode, leaving your monitor blind. The Roadmaster Stop Light Switch Kit solves that by providing a dedicated 12-volt signal that stays live during towing. It’s a dependable way to make sure your supplemental braking system and monitor stay in sync even when the factory wiring won’t cooperate.
Flat towing can be a much more convenient way to take your car RVing with you than using a trailer or a tow dolly. It'll save you storage space both at home and at the campsite, and it takes less time and hassle to hook up.
To flat tow your vehicle, there are 5 basic components you're going to need: a tow bar, a base plate kit, a safety cable set, tow bar wiring, and a flat tow braking system.
| For the RV | Between the RV and Towed Car | For the Towed Car |
|---|---|---|
| Hitch | Tow bar | Base plate |
| Wiring plug | Safety cables | Braking system |
| Wiring adapter cord | Wiring kit/diodes |
The custom-fit base plate installs on the frame of your toad so you can connect the car to your RV with a tow bar. Hook up safety cables between the vehicles to ensure that the toad does not separate from the motorhome if the tow bar becomes detached. Tow bar wiring syncs your vehicle's signal lights with your motorhome's tail lights, as required by law in most states. Finally, the flat tow braking system - also required in most states - activates the brakes in the toad when you hit the brakes in the RV, making for smoother, safer braking, and preventing wear on your motorhome.
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hi, everyone, Steve here with etrailer.com. Today we're looking at the Roadmaster Stoplight Switch Kit, specifically for a '22 to '24 Lincoln Navigator. Now, that being said, make sure you double-check the fit guide here at etrailer.com. Enter things like year, make, and model, make sure you're getting the right parts the first time. Now, a stoplight switch is going to activate your motorhome's brake monitoring system whenever you brake, and that brake pedal is applied in the tow vehicle. It's gonna ensure that the supplemental braking system is functioning properly.
It ensures that, or it works great rather for any application that does not have a tow position in the ignition. Now, this does wire directly into the car's, the tow car's fuse box for consistent current. And it's 12 volt. You got the fuse tap here, the inline fuse, two butt connectors, two different lengths of wire that are colored, and of course, the stoplight switch and the custom bracket. Well, folks, that's gonna wrap it up for our quick look together.
I'm Steven. Thanks for watching.
Ratings & Reviews
Victoria H.
1/14/2025
That's quite impressive Fred, nice ride!
Fred
1/8/2026
Everything works just fine! Great product and support! Thanks E-t
Josh B.
1/8/2026
Alan
9/8/2026
Its been a year and to be honest, I never have to think about my tow setup. Its there, it works perfect like the day I got it. I cant recommend this any higher. Smooth towing without worrying about it.
Lazer S.
9/8/2026
Kate F.
12/17/2025
I wish you could mount it there Donald, but those stop-light-switch studs are only designed to hold the switch bracket. Adding the pulley bracket changes the spacing and alignment, which can make the brake lights stay on, not come on, or throw off the Invisibrake’s operation. The studs also aren’t meant to handle the side-load from the cable, so Roadmaster doesn’t recommend using them. For drilling stainless, the trick is a cobalt bit (M35 or M42), slow speed, steady pressure, and cutting oil so the metal doesn’t work-harden. Are you new to flat towing, or just getting a different vehicle set-up?
Michael R.
1/18/2024
Still working great
Mark S.
11/3/2025
Its a good choice because its easy in easy out. I have two jeeps that can flat tow, so i was covered for braking in either one
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Kate F.
4/23/2026
Thank you for the detailed review and for sticking with the install George. That is a tight space to work in, and we really appreciate you sharing both the challenges and your thought process along the way. You make some very valid points about the alignment sensitivity and adjustability of the switch. I agree, that kind of precision fit without an easy lateral adjustment can make the install more tedious than it should be. It does not make it right, and feedback like this is exactly what helps highlight areas for improvement. It is great to hear that it has been working reliably for you over a few thousand miles so far. Your habit of checking function during hookup is a solid practice and definitely the way to go with setups like this. I will be passing your feedback along to the manufacturer for review, especially your notes on the switch design and mounting adjustability. Also, thank you for including photos even with the tight space. They are very helpful for others tackling the same install.