1995 GMC Sonoma Owner's Manual - Page 113

Volfrneter Gage 14 When your engine is not running, but the ignition is on (in the RUN position), this gage shows your battery's state of charge in DC volts. When the engine is running, the gage shows the condition of the charging system. Readings between the low and high warning zones indicate the normal operating range. Readings in the low warning zone may occur when a large number of electrical accessories are operatingin the vehicle and the engine is left at an idle for an extended period. This condition is normal since the charging system is not able to providefull power at engine idle. As engine speeds are increased, this condition should correct itself as higher engine speeds allow the charging system to create maximum power. You can only drive for ashort time with the reading in either warning zone. If you must drive, turn off all unnecessary accessories. Readings in either warning zone indicate a possible problem in the electrical system. Have the vehicle serviced as soon as possible. Center High Mounted Stop Lamp (CHlWSL) Feed Wire Your vehicle includes a Center High Mounted Stop Lamp (CHMSL)located above the rear window. If e.quipment such as a cap or camper installed, a wire labeled "Center is High Mounted Stop Lamp (CHMSL)"feed is provided along the left rear frame. This wire should be used to install a CHMSL in the cap orcamper. 2-67