the wiring to all of the upper gate goes through the right "accordeon" boot... the left boot is for the hose for washer fluid...

the harness for third light splits at entry point from rest of wires and goes into the spoiler... the rest of wires go to the wiper motor area... if it weren't for the stop light, i would say the plug at the motor needs checked...

pull the trim - 4 screws, two in the handles, two under lights - then pop the push-in pins... the side trims are very hard to disengage from bottom trim, but there are no more screws to unscrew... check the motor plug, check the wires for chaffing...