Is Brake-Lite Relay for 2017 GMC Acadia Needed To Flat Tow?

Question:

I have conflicting answer on whether I need the Roadmaster Brake-Lite Relay on my 2017 GMC Acadia not Limited. Your Jason S replied no needinch in previous QandA. Roadmaster literature says if the brake lights do not illuminate after stepping on brakes after vehicle is off, you dont need it. My brakes lights come on with vehicle off. Unless opening the door to hit the brakes sets them on?

asked by: Ken W

Expert Reply:

Since your brake lights illuminate when the vehicle is off, as long as that doesn't stop after a specific amount of time, you will not need the Roadmaster Stop Light Switch Kit # RM-751483. This kit is designed to make sure there is a constant power to the brake light switch so you get an accurate read in your motorhome of when the brakes of your towed vehicle are being applied.

Since you have stated that you have brake lights when the vehicle is off, you already have a stop light switch that is compatible with the system. You can add another without issue if desired instead of splicing wires. Opening the door of your vehicle will not trigger brake lights to work or not unless there is a timing delay as stated in the attached photo.

I've attached a photo of the installation instructions to assist where I've highlighted when this components is needed. Roadmaster does state that the part is needed but there is conflicting information so you will need to go by function.

expert reply by: Jason S