GM Service Manual Online
For 1990-2009 cars only

The CTSY (fuse 3) supplies the voltage at all times to the following lamps:

    • The courtesy lamps
    • The dome/reading
    • The vanity
    • The instrument panel compartment

The courtesy and dome lamps turn on when one of the following switches provides a ground path:

    • The headlamp and panel dimmer
    • One of the door jambs

Individual switches provide the ground paths when the switches close for the following lamps:

    • The instrument panel compartment
    • The vanity

The AUX PWR (fuse 7) supplies the voltage at all times to the front and the rear power outlets. Ground G200 provides the ground to the front power outlet. Ground G400 provides the ground to the rear power outlet. CIG LTR (fuse 13) supplies the voltage at all times to the cigarette lighter. Ground G200 supplies the ground to the cigarette lighter.

Component Illumination Lamps Circuit Description

When the headlamp and panel dimmer switch is in the PARK or the HEAD position, voltage applies through the PK LPS (fuse 9) and the closed contracts of the headlamp and panel dimmer switch to the component illumination lamps. The following grounds provide the grounds to the component illumination lamps:

    • G105
    • G107
    • G200

When the grounds apply, the path is complete. When the path is complete, the lamps light.

Illuminated Entry W/RKE Circuit Description

The illuminated entry system (part of the remote control door lock receiver) activates when the door opens. When the door closes, the dome lamps remain illuminated for approximately 20 seconds. The lamps will also remain illuminated until the ignition switch is in the ON position. The functions cancels when the ignition switch is in the ON position. CTSY (fuse 3) supplies the voltage to the remote control door lock receiver at all times. CKT 1050 (BLK) provides the ground path through ground G200. The remote control door lock receiver senses a ground signal from CKT 157 (GRY) when a door opens. The remote control door lock receiver then provides a ground path to CKT 156 (WHT). The lamps illuminate when the ground path is provided.

Illuminated Entry W/O RKE Circuit Description

The interior lamp control module activates when the door opens. When the door closes, the dome lamps remain illuminated for approximately 20 seconds. The lamps will also remain illuminated until the ignition switch is in the ON position. The functions cancels when the ignition switch is in the ON position. CTSY (fuse 3) supplies the voltage to the interior lamp control module at all times. CKT 1050 (BLK) provides the ground path through ground G200. The interior lamp control module senses a ground signal from CKT 157 (GRY) when a door opens. The interior lamp control module then provides a ground path to CKT 156 (WHT). The lamps illuminate when the ground path is provided.