So awhile back I broke the passenger side mirror on the Excursion. The guy that had it before me had switch these out to 08-10 mirrors back before I got it in 2013. He cut the harness off then and wired them up. But my question is how do I figure which wires operate up/down/left/right. I figured out the lights so far. I’ve tested power to all the other wires with test light on each wire while moving mirror joystick and I do t get anything.