Circuit Operation - HUD Image Intensity Control

The Head Up Display (HUD) control module monitors CKT 717 (WHT) at terminal 3 to determine the image intensity. When the HUD control switch is ON, the DIM to BRIGHT switch varies the voltage at terminal 7 of the MUD control switch. when the HUD control module detects that the park lights are off (CKT 32, YEL), the HUD control module uses the input at terminal 3 to adjust the image intensity to the desired level. When the MUD control switch is OFF, terminal 7 is connected to ground at terminal 10 (CKT 251, BLK/WHT) of the MUD control switch. When the MUD control module detects a low (ground) condition at terminal 3 (CKT 717, WHT) the HUD image turns OFF.