For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningDome Lamps
The dome lamp controls are in the headliner.
(Dome Lamp Override): Press
to turn the lamps off, even when a door is open.
(Door): Press to turn the
lamps on automatically when a door is opened.
(On): Press to turn on the
dome lamps. ...
Front Side Door Wiring Harness Replacement
Preliminary Procedure
Remove the front side door inner panel trim. Refer to Front Side Door Trim
Replacement.
Front Side Door Wiring Harness
Warning: Unless directed otherwise, the ignition and start switch must be
in the OFF or LOCK position, and all electrical
loads must be OFF before ...
Lighting
Specifications
Headlights/Daytime Running Lights (DRL) Schematics
Interior Lights Schematics
...