2002 GMC Envoy Owner's Manual - Page 371

Electrical System Add-On Electrical Equipment Headlamps The headlamp wiring is protected by four fuses. An electrical overload will cause a lamp to go on and off. If this happens, have your headlamp wiring checked right away. NOTICE: Don't add anything electrical to your vehicle unless you check with your dealer first. Some electrical equipment can damage your vehicle and the damage wouldn't be covered by your warranty. Some add-on electrical equipment can keep other components from working as they should. Your vehicle has an air bag system. Before attempting to add anything electrical to your vehicle, see "Servicing Your Air Bag-Equipped Vehicle" in the Index. Windshield Wipers The windshield wiper motor is protected by a circuit breaker and a fuse. If the motor overheats due to heavy snow or ice, the wiper will stop until the motor cools. If the overload is caused by some electrical problem, be sure to get it fixed. Power Windows and Other Power Options Circuit breakers protect the power windows and other power accessories. When the current load is too heavy, the circuit breaker opens and closes, protecting the circuit until the problem is fixed or goes away. 6-56