GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 Seville 🢒 Body and Accessories 🢒 Cellular Communication 🢒 OnStar Schematics
Figure 1:

Power, Ground, and Onstar Keypad (Early Production)
Object Number: 879888 Size: FS
Figure 2:

Power, Ground, and Onstar Keypad (Late Production)
Object Number: 1202041 Size: FS
Figure 3:

Microphone and Audio Amplifier (Early Production)
Object Number: 789529 Size: FS
Figure 4:

Microphone and Audio Amplifier (Late Production)
Object Number: 1202028 Size: FS