This is from 2011 Chevy Equinox owner's manual.
Location: The electrical cord is located on the passenger side of the engine compartment, in front of the air cleaner.
Engine Coolant Heater
The engine coolant heater, if available, can help in cold weather conditions at or below −18°C (0°F) for easier starting and better fuel economy during engine warm-up. Plug in the coolant heater at least four hours before starting the vehicle. An internal thermostat in the plug-end of the cord will prevent engine coolant heater operation at temperatures above −18°C (0°F).
To Use The Engine Coolant Heater
- Turn off the engine.
- Open the hood and unwrap the electrical cord.
The electrical cord is located on the passenger side of the engine compartment, in front of the air cleaner.
- Plug it into a normal, grounded 110-volt AC outlet.
- Before starting the engine, be sure to unplug and store the cord as it was before to keep it away from moving engine parts. If you do not it could be damaged.
The length of time the heater should remain plugged in depends on several factors. Ask a dealer in the area where you will be parking the vehicle for the best advice on this.
Warning: 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.
