I Have Power Going Into 6 Way Plug to Flat Tow My 22 GMC Canyon But My Tail Lights are Not Working?
Updated 03/26/2025 | Published 03/09/2025
Question:
I just hooked up my 2022 GMC Canyon AT4 to my 2023 Georgetown MH. I have turn and stop lights but no tail lights. I have power at the MH plug and power at the 6 pin on the GMC Canyon. But when I got to the taillights I have no power.
asked by: Rj F
Expert Reply:
Hello RJ,
Sorry to hear you’re having issues with your Roadmaster diode wiring. I see that you placed the order last July, when you first set everything up, were the tail lights working, or is this your first time hooking it up?
I just looked up your order, and I don’t see a brake light relay included. The 2022 GMC Canyon AT4 requires one, and not having it installed can cause this exact issue. If you don’t already have one, you’ll need the Roadmaster Universal Stop Light Switch Kit # RM-751000. This kit prevents the towed vehicle’s brake signal from interfering with the motorhome’s tail light wiring. Without it, the brake lights could override the tail light signal, which would explain why you have turn signals and brake lights but no tail lights. I’ve attached a video for you to check out as well.
Let me know if you already have the relay installed. If you do, we’ll need to dig a little deeper to figure out what’s causing the issue. Got a big trip coming up you’re getting ready for?
Product Page this Question was Asked From
Roadmaster Universal Stop Light Switch Kit
- Flat Tow Brake System
- Stop Light Switch
- Roadmaster
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on Flat Tow Brake System
Rj
3/19/2025
Kate, Thank you for the response and I had the diode kit from my previous 2023 GMC Canyon elevation. Was not able to use the Elevation as it did not have a 2 speed transfer case to flat tow so I had to get rid of it. I also found out that the front tow mounts were different so I had to purchase those for the 2022 GMC AT4. I will order the stop light switch and hopefully that will fix the problem. Thank you, RJ