System Operation

The twilight sentinel system operates automatically whenever the ignition switch is on, the headlamp switch is off, and driver control is turned on (any position other than off). The system will turn on the lamps when the daylight is reduced to a point at which illumination is necessary.As daylight increases in the morning and illumination is no longer necessary, the system will turn off the lights.

A time delay feature reduces the frequency of undesired switching of the lamps while passing under viaducts, trees, bright lights, etc.The time delay is normally 8 - 20 seconds, and cannot be altered or adjusted. The potentiometer controls only the time delay period during which lamps will remain on after the ignition is turned off.The driver may preselect any desired time delay, from a few seconds to a maximum of 180 seconds.

Slide the potentiometer to the OFF position when the lamps are undesirable, such as driving in tunnels that require lamps off, or if the twilight sentinel malfunctions. This disables the twilight sentinel.The lamps will now operate only with the regular lamp switch.If the lights are desirable during daylight hours, the driver can use either of 2 methods to turn the lights on:
1. Turn on the lamps by operating the regular lamp switch. The headlamp switch is wired in parallel with the twilight sentinel. This bypasses the system, whether the control potentiometer is on or off.If this method of manual operation is selected, the lamps will remain on after the ignition is turned off.When the driver opens the door to leave the vehicle, an audible warning reminds the driver to turn off the lamps if the ignition is turned off.The audible alarm sounds a double chime warning when the ignition is off and headlamp switch is left on (in either the headlamps mode or the park lamps mode) and the driver's door is open.
2. Cover the photocell in order to prevent any light exposure.This causes the lamps to turn on and still permit the twilight sentinel to turn lamps off in the normal manner when ignition is turned off. If the cell has been exposed to light, the time delay must elapse before the lamps will turn on.