2004 Chevrolet Impala Owner's Manual - Page 90
2004 Chevrolet Impala Manual
Page 90 highlights
Engine Coolant Heater To Use the Engine Coolant Heater 1. Turn off the engine. 2. Open the hood and unwrap the electrical cord. The cord is attached to the underside of the diagonal brace, which is located above the engine air cleaner/filter assembly. 3. Plug it into a normal, grounded 110-volt AC outlet. {CAUTION: Plugging the cord into an ungrounded outlet could cause an electrical shock. Also, the wrong kind of extension cord could overheat and cause a fire. You could be seriously injured. Plug the cord into a properly grounded three-prong 110-volt AC outlet. If the cord will not reach, use a heavy-duty three-prong extension cord rated for at least 15 amps. Your vehicle may be equipped with this feature. In very cold weather, 0°F (−18°C) or colder, the engine coolant heater can help. You'll get easier starting and better fuel economy during engine warm-up. Usually, the coolant heater should be plugged in a minimum of four hours prior to starting your vehicle. At temperatures above 32°F (0°C), use of the coolant heater is not required. 2-22