Hi: I have done one in a 2020 Lariat with my son. You have to pull the headliner down a little in the back driver corner. you need to pull the seat belt connection and side trim off the driver's side. We also pulled the 3rd brake light off the back of the cab and reached in with fingers to locate the clip that holds the wire in place and then dropped the wire connector down to see color and made up the proper connector. connect the two new connectors and push them behind headliner and reinstall the light and rest of trim.
Race red ranger, Where did you mount the switch? Thanks, Earl
in the lower left panel that hinges down where you made the wire connection. The panel has a recess about 1 inch by 2 inches. Hard to see but after you set it up you don't need to see the lights in the push button but you can still reach if required to push or adjust.
