Briit in SC

I have a message on my dash that says the right brake light should be checked. It is LED. The LED functions with remotely supplied power. All other right side lights function and they seem to use a common ground strip. My other two brake lights remain illuminated when the car is running. I cleaned both connections to the LED strip with sandpaper. They looked fine initially but i cleaned them anyway. The electrical connection to the entire taillight assembly looks good.

wallyp

Start at the wire and check at every connection to see where the power disappears.

Briit in SC

I get that. I have searched on-line for a wiring diagram but admittedly I am not the best troubleshooter. Why would my other two brake lights remain illuminated while the car is running?