I can tell you that most electrical engineers make the worst phone line repair guys...
Anyways, at night park somewhere dark, sit in the drivers seat and look in the rearview, and get someone to hold a bright flashlight and shine it through the rear window onto the mirror.
With no light hitting the front sensor, and lots of light hitting the sensor facing the rear, it should start to darken slowly to a green colour.
The flashlight should look greenish in the rearview.
DEI 2-way Alarm & Start / DDM Ballasts + CAP 6000k 55w HIDs in Eagle Eyes Projectors / 6000k 55w HID Fogs / All INT+EXT LEDs+7W LED Reverse / K&N Air Filter / Kumho Ecsta 4X Tires / 35%/20% Tint / Black Grille / Maxxsonics MX-1 + 2500W Stereo