Automatic Day/Night Mirror: Operation

A switch located on the bottom of the automatic day/night mirror housing allows the vehicle operator to select whether the automatic dimming feature is operational. When the automatic day/night mirror is turned on, the mirror switch is lighted by an integral LED. The mirror will automatically disable its self-dimming feature whenever the vehicle is being driven in reverse.

The ambient photocell sensor is located on the forward-facing (windshield side) of the mirror housing and detects the ambient light levels outside of the vehicle. The headlight photocell sensor is located inside the mirror housing behind the mirror glass and faces rearward, to detect the level of the light being received at the rear of the mirror. When the circuitry of the automatic day/night mirror detects that the difference between the 2 light levels is too great (the light level received at the rear of the mirror is much higher than that at the front of the mirror), it begins to darken the mirror.

The automatic day/night mirror circuitry also monitors the transmission using an input from the backup light circuit. The mirror circuitry is programmed to automatically disable its self-dimming feature whenever it senses that the transmission backup light circuit is energized.

The automatic day/night mirror is a completely self-contained unit and cannot be repaired. If faulty or damaged, the entire mirror assembly must be replaced.