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When you’re flat towing, you need to know what’s really happening with your towed car’s brakes. The Roadmaster Stop Light Switch Kit ties directly into the brake pedal so your RV’s monitoring system lights up only when the pedal is actually pressed. Unlike systems that just sense air cylinder movement, this one tells you what’s going on at the pedal itself. That means you’ll know your supplemental braking system is working right every time you stop.
A misaligned or overactive braking system can keep pressure on the pedal even when you’re not braking, which can wear out tires and components fast. This stop light switch helps prevent that by confirming that the pedal is fully retracting after every stop. It’s a simple way to avoid costly damage and keep your towing setup reliable mile after mile.
The kit wires directly into your towed car’s fuse box for a constant current source and runs on 12 volts. That steady power supply ensures your braking monitor works consistently, so you always have a real-time signal whenever the pedal moves. It’s a dependable, no-guesswork setup that just works.
If your ignition doesn’t have a tow position, this kit still keeps your brake monitoring active. It gives you the same confidence and situational awareness as setups that do, so your supplemental braking system functions smoothly and predictably every trip.
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.
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
Do you have a question about this Flat Tow Brake System?
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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.