Section 13 (Analog Instrument Panels): Operation: Gauges: Voltmeter
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 GMC Savana Special, 2001 GMC Savana Camper Special, 2001 GMC Savana, 2001 Chevrolet RV Cutaway, and 2001 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
Voltmeter displays vehicle system voltage level. IPC uses ignition 1 voltage circuit in order to display a voltage level on voltmeter.