This is a complete Mirror Controller Swap for a Grand Wagoneer, Wagoneer and possibly other Full-Sized Jeeps (FSJ). The Upgraded Mirror Controller is from a 93-95 Grand Cherokee (Specifically in this video from a 1994 Grand Cherokee)
Every write up and video has small deviations and nuances, I tried to cover all the information found in the write up on International Full Size Jeep Associations Forum, but in the end my 1987 Grand Wagoneer Upgrade was slightly different.
Do your research, follow the instructions and double check your connections before making them permanent.