GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2009 🢒 Lucerne 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Headlights/Daytime Running Lights (DRL) Schematics
Figure 1:

Headlamps
Object Number: 2081604 Size: FS
Figure 2:

Headlamp Switch
Object Number: 2081609 Size: FS