C 2500 Truck 2WD V8-5.7L VIN R (1997)
Underhood Lamp: Technical Service Bulletins
Lights - Revised Circuit Operation, Interior & Underhood
File In Section: 8 - Chassis/Body Electrical
Bulletin No.: 76-81-10
Date: August, 1997
SERVICE MANUAL UPDATE
Subject:
Section 8A-114 Interior Lights - Revise "Circuit Operation"
Models:
1997-98 Chevrolet and GMC C/K Models
This bulletin revises "Circuit Operation" on Page 8A-114-19 in the 1997 C/K Service Manual and Page 8A-114-17 in the 1998 C/K Service Manual.
INTERIOR LAMPS
CIRCUIT OPERATION
Voltage is supplied at all times from the CTSY Fuse 3 to the Courtesy Lamps, Dome and Reading Lamps, and IP Compartment Box Lamp. The Courtesy
and Dome and Reading Lamps turn on when a ground path is provided by the Headlamp and Panel Dimmer Switch or one of the Door Jamb Switches.
The IP Compartment Box Lamp and Vanity Lamps have switches that provide ground paths when the switches close.
For Suburban and Utility Vehicles that are equipped with Power Door Locks the Rear Cargo Door Jamb Switch wire is ORN (1897) which comes off the
Power Door Lock Control Module and the Base Body Rear Cargo Door Jamb Switch wire is PPL (328) which comes off the Connector C302 Cavity C.
UNDERHOOD REEL LAMP
Voltage is supplied at all times to the Underhood Reel Lamp from the HORN Fuse. When the switch is closed, a ground path is provided.
COMPONENT ILLUMINATION LAMPS
When the Headlamp and Panel Dimmer Switch is turned to the PARK or HEAD position, voltage is applied through the PARK LPS Fuse 9 and the
closed contacts of the Headlamp and Panel Dimmer Switch to the Component Illumination Lamps. Since all of the Component Illumination Lamps are
grounded through Ground G200, the lamps light.
ILLUMINATED ENTRY
When a door is opened, the Illuminated Entry System is activated. After the last door is closed, the Dome and Reading Lamps will remain illuminated for
20 seconds or until the Ignition Switch is turned on. Voltage is supplied to the module at all times through CTSY Fuse 3. The ground path is provided by
CKT 150 to Ground G200. The module senses a ground signal from CKT 157 when a door is opened. The module then provides a ground path to CKT
156 which allows the lamps to light.
