2008 Dodge Ram 2500 Pickup Owner Manual Diesel - Page 191

UNDERSTANDING YOUR INSTRUMENT PANEL 189 INSTRUMENT CLUSTER DESCRIPTION 1. Check Gauges This light illuminates when the Voltmeter, Engine Oil Pressure or Engine Coolant Temperature gauges indicate a reading either too high or too low. Examine the gauges carefully, and follow the instructions contained below for each indicated problem. NOTE: When the ignition switch is turned to OFF, the Fuel Gauge, Voltmeter, Oil Pressure and Engine Coolant Temperature gauges may not show accurate readings. When the engine is not running, turn the ignition switch to ON to obtain accurate readings. 2. Voltmeter When the engine is running, the gauge indicates the electrical system voltage. The pointer should stay within the normal range if the battery is charged. If the pointer moves to either extreme left or right and remains there during normal driving, the electrical system should be serviced. NOTE: If the gauge pointer moves to either extreme of the gauge, the "Check Gauges" indicator will illuminate and a single chime will sound. NOTE: • The voltmeter may show a gauge fluctuation at various engine temperatures. This cycling operation is caused by the post-heat cycle of the intake manifold heater system. The number of cycles and the length of the cycling operation is controlled by the engine control module. Post-heat operation can run for several minutes, and then the electrical system and voltmeter needle will stabilize. • The cycling action will cause temporary dimming of the headlights, interior lights, and also a noticeable reduction in blower motor speed. 4