2008 Jeep Wrangler Owner's Manual - Page 276

STARTING AND OPERATING 275 ENGINE BLOCK HEATER - IF EQUIPPED The engine block heater warms engine coolant and permits quicker starts in cold weather. Connect the cord to a standard 110-115 Volt AC electrical outlet with a grounded, three wire extension cord. The engine block heater cord is found under the hood bundled in front of the battery tray. MANUAL TRANSMISSION WARNING! You or others could be injured if you leave the vehicle unattended without having the parking brake fully applied. The parking brake should always be applied when the driver is not in the vehicle, especially on an incline. WARNING! Remember to disconnect the cord before driving. Damage to the 110-115 Volt AC electrical cord could cause electrocution. Use the heater when temperatures below 0°F (-18°C) are expected to last for several days. 5 CAUTION! Never drive with your foot resting on the clutch pedal, or attempt to hold the vehicle on a hill with the clutch pedal partially engaged, as this will cause abnormal wear on the clutch.