GMC 2009 Sierra - Manual (Page 420)

Electrical System
Add-On Electrical Equipment
Notice: Do not add anything electrical to your
vehicle unless you check with your dealer/retailer
first. Some electrical equipment can damage
your vehicle and the damage would not be
covered by your warranty. Some add-on electrical
equipment can keep other components from
working as they should.
Add-on equipment can drain your vehicle’s battery,
even if your vehicle is not operating.
Your vehicle has an airbag system. Before attempting
to add anything electrical to your vehicle, see Servicing
Your Airbag-Equipped Vehicle on page 1-68.
Windshield Wiper Fuses
The windshield wiper motor is protected by an internal
circuit breaker and a fuse. If the motor overheats
due to heavy snow, etc., the wiper will stop until the
motor cools. If the overload is caused by some electrical
problem and not snow, etc., be sure to get it fixed.
Power Windows and Other
Power Options
Circuit breakers protect the power windows and other
power accessories. If the current load is too heavy,
the circuit breaker opens and then closes after a
cool down period, protecting the circuit until the
problem is fixed or goes away.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance of fires caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure
you replace a bad fuse with a new one of the identical
size and rating.
If you ever have a problem on the road and don’t
have a spare fuse, you can borrow one that has the
same amperage. Just pick some feature of your
vehicle that you can get along without – like the radio
or cigarette lighter – and use its fuse, if it is the correct
amperage. Replace it as soon as you can.
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