2010 Hummer H3T Owner's Manual - Page 152

6-8 Lighting Dome Lamp Override The dome lamp override button is located below the exterior lamps control. E (Dome Lamp Override): Press the button in to turn the lamps off. In this position, the dome lamps will remain off when the doors are open. To return the lamps to automatic operation, press E again and return it to the out position. With the button in this position, the dome lamps will come on when a door is opened. Lighting Features Exit Lighting The interior lamps come on when the key is removed from the ignition. The lamps will not come on if the dome override button is pressed in. Battery Load Management The vehicle has Electric Power Management (EPM) that estimates the battery's temperature and state of charge. It then adjusts the voltage for best performance and extended life of the battery. When the battery's state of charge is low, the voltage is raised slightly to quickly bring the charge back up. When the state of charge is high, the voltage is lowered slightly to prevent overcharging. If the vehicle has a voltmeter gauge or a voltage display on the Driver Information Center (DIC), you may see the voltage move up or down. This is normal. If there is a problem, an alert will be displayed. The battery can be discharged at idle if the electrical loads are very high. This is true for all vehicles. This is because the generator (alternator) may not be spinning fast enough at idle to produce all the power that is needed for very high electrical loads. Reading Lamps The reading lamps are located in the overhead console. Press the button located next to each lamp to turn them on or off. These lamps will not come on with the dome lamps.