Installing Self-Dimming/Compass/Temp. Mirror in '90 Truck

[CheySuper8]

I know the temp. sensor wires are brown and light green with a black stripe,the heavy gauge black wire is ground,the pink wire is power supply,and the plain light green should go to the back up lights to prevent dimming in reverse. What I need to know is what the gray wire hooks to and what it does and what the light pink wire hooks to and what it does. This mirror is from a 98 or newer Chevy truck, I think. I would appreciate any information anyone has. Thanks! Ken