Do I Need a Brake Light Relay for a 2025 Ford Ranger?

Updated 11/13/2026 | Published 11/11/2026

Products Featured in This Question

Roadmaster Brake-Lite Relay Kit for Towed Vehicles

(786)

$39.95

Question:

I have a 2025 ford ranger xlt. Im a bit confused about the turn signal brake light overriding issue? Online , I have read that if you have a ford vehicle that has a factory neutral tow feature in settings mine has recreational tow and if you do you should not install the brake light relay kit as it could damage the transmission. I am planning on wiring the lights using the smart diodes that are recommended for the ford ranger. I have read that if youre using the smart diodes that you do not need the brake light relay kit, that the smart diodes will handle the brake lights overriding turn signal issue. I talked to somebody at e trailer yesterday. Who said that you needed to use the brake light relay kit to solve this problem. So, Im getting mixed information about what I should do. I obviously do not want to damage the transmission. can someone that is knowledgeable about this issue and knows for certain what to do please confirm with me what route I should take when wiring my tow vehicle lights. thank you, Steve

asked by: Steve S

Expert Reply:

Hi Steve,

I'm sorry for all the confusion, while the smart diodes do separate the running lights from the brake lights and prevent constant brake lights, they don't stop the truck's brake pedal switch from sending the signal to the taillights when the braking system presses the pedal. When you hit the brakes on your motorhome the braking system will press the pedal on the Ranger and without the relay the Ranger's brake light circuit will override the blinking turn signal light from the motorhome.

A brake light relay could only cause damage to the transmission if it is installed incorrectly. A 2025 Ford Ranger uses an electronic 'Neutral Tow' mode that requires pressing and holding the brake pedal while navigating the dash menu. You will always need to complete the Ford Neutral Tow mode before turning on the RV's headlights or running lights. Once the RV lights are on, the relay activates and blocks the Ranger's brake pedal signal so it can't overrie the RV's turn signals. The Roadmaster instructions that come with the brake light relay have an 'A' and 'B' option depending on the vehicle's ignition. Your 2025 Ford Ranger should have a push button ignition which means you'll need the 'B' instructions. I've linked the instructions so you can take a look at them. We've had plenty of people install a brake light relay on their Ford Rangers and have done plenty of installs here at our facility as well. As long as its done properly, there is no risk to the transmission.

Are you planning on having a shop install the relay or doing it yourself?

expert reply by: Claire H

Dan H.

11/13/2026

My 2018 F150 did not need the brake light relay because I used the diodes and the turn signals use a different bulb on mine .

Claire H.

11/13/2026

@DanH The 2018 Ford F150 uses combined wiring and has a standard 12V on/off circuit that doesn't bleed 6V running-light current onto the brake wire, so a brake light relay isn't necessary for your truck. The 2025 Ford Ranger needs a brake light relay because a single bulb in each taillight performs two different jobs—acting as both the brake light and the turn signal—and cannot receive two conflicting electrical commands at the exact same time