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How to Wire Brake-Lite Relay Kit on 2024 Ford Maverick Hybrid  

Updated 07/11/2026 | Published 08/27/2025

Question:

Hi, I have a 2024 Hybrid Maverick Lariat and am setting it up for flat towing with my class A RV 2025 Entegra Vision 29S. I have read many posts on your site and I have decided to use the following: Demco baseplate Demco Commander II tow bar Demco Stay-IN-Play Duo supplemental brake system Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit Roadmaster Battery Charge Line Kit for Towed Vehicles However, I am unsure about using the Roadmaster Brake-Lite Relay Kit. The hybrid Maverick does not have a brake light relay, but has a brake pedal switch that feeds the Body Control Module. How would I wire in the brake lite relay kit in this instance? Thanks and have a nice evening Albert

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Expert Reply:

Hey Albert! The Roadmaster Brake-Lite Relay Kit # RM-88400 is going to tie into the cold side of your brake light switch. On the 2024 Ford Maverick Hybrid that is a light purple wire with a white stripe. If you scroll down a little further on this page you will see I linked a video where we installed this on another 2024 Maverick Hybrid so you can use that as a guide.

The Demco setup is nice but have you considered our etrailer branded parts? The etrailer Invisible Base Plate Kit # e64FV and etrailer SD Non-Binding Tow Bar # e34ZR share the same design so you can save a little money going this route. Outside of that, it looks like you're all set with the rest of your parts. I'll list them below so you have it all here on this page.

-Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit # RM-15267

-Roadmaster Battery Charge Line Kit for Towed Vehicles # RM-156-25

-Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes # SM99251

Any big trips planned this fall once you get everything installed on your Maverick?

expert reply by:
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Robin H
2024 Maverick Brake Light Switch Wire
2024 Maverick Brake Light Switch Wire
(click to enlarge)
Albert O. profile picture

Albert O.

8/28/2025

Thanks Robin. I thought that might be the case with the brake light switch, but wanted to make sure. I already have the baseplate but will consider the eTrailer branded tow bar. Hopefully will have this all set up before our trip to Acadia at the end of September!

Robin H. profile picture
Etrailer Expert

Robin H.

8/28/2025

@AlbertO happy to help, all of the wiring can definitely get complicated. Since they're the same, our tow bar will work with that Demco base plate you already have without the need for any adapters. Acadia National Park in Maine? Sounds like a great trip, enjoy!
Albert O. profile picture

Albert O.

7/10/2026

Hi, I am finally getting to installing everything to flat tow my 2024 Ford Maverick. I purchased and installed everything suggested. Followed all of the instructions in the videos. They were a GREAT help! thanks. I have one remaining problem and that is with the brake light relay. When I plug into the 7 pin on my RV, the brake lights come on and blinkers do not work and the brake is not depressed. I thought that I may have mis-wired or had a bad ground and looked at everything again and it looked good. When I searched for a possible solution, Google's AI said not to tie both purple/white wires together as this can cause voltage to bleed into the BCM causing potential faults or computer damage. Both wires from the "hot" side get 12V when the brake light is depressed. So, I took the relay out of the circuit to try and test to see what is going on. By doing a resistance check I was able to determine which of the cold side wires go to the rear taillights and which one goes to the BCM (lower resistance to the LED lights). If I keep the BCM wire connected to a hot side wire coming from the brake switch and keep the brake light pair open, the brake lights still come on when the maverick brake pedal is depressed. Before I wire the relay back in, does this make sense? I have not yet done any further testing plugged into the RV as it will not be able to do that until tomorrow. Also, with the brake light pair open and the BCM pair closed, I get a proximity sensor fault when the car is powered on. I imagine that doesn't matter when towing and the vehicle is in neutral tow mode. I guess my question is are you sure about tying both purple/white pairs together? The video does not mention to do this, but it is obvious from the pictures to see that is what was done. Thanks for your help Albert

Robin H. profile picture
Etrailer Expert

Robin H.

7/11/2026

@AlbertO thanks for the detailed follow-up. We did tie the two purple/white wires together during our Maverick installation, and that's still how Roadmaster identifies the brake light switch wire for the # RM-88400. If the brake lights come on as soon as you plug into the RV, I'd also suspect 12V is feeding back through the tow wiring or there's an issue at the 6-way/7-way connector. Since you've already done quite a bit of testing, I'd give Roadmaster a call before changing the brake switch wiring. They can confirm the Maverick wiring and determine whether the issue is with the relay or somewhere in the tow wiring while actively troubleshooting with you at the vehicle.

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