The fuses are the heart of your Chevy’s electrical system. Nearly every system in a car that requires battery or electric power (windows, door locks, lighting, stereo, etc. etc.) is wired and powered through a fuse. The battery sends power to the fuse which then transfers it to the specific system on the car. The purpose of a fuse is to prevent the battery from directly overloading and melting a systems wiring.
When a fuse becomes overloaded, or is carrying too many amps of power for its capacity, the fuse breaks. When a fuse breaks, it cuts off the power supply to that specific system. So when you experience an electrical-related failure in your car, the fuses are the first place you should look.
Fuses are extremely important as they protect all of our electrical components. If your battery ran its power directly to your stereo instead of through a fuse first, if the battery accidentally overloaded the stereo it would break everything. And then you’d need to spend a few thousand dollars replacing your full stereo system instead of $0.50 replacing the fuse.
Types of Chevy & GMC Fuses
Fuses come in different colors and different sizes. The color and size of the fuse depict the amount of power (in amps) the fuse is capable of supplying. Stereo systems require a lot of electrical power, so they will usually have a bigger and more powerful fuse than say the power windows.
The amp rating is usually marked right on the top of the fuse. However, coloring can also help you identify its amp rating. You need to be careful to use the correct fuse when replacing a bad one. While some of the different sizes will not fit into the fuse box, ie. a 5amp fuse will not fit in a 40amp fuse slot, there are a lot of different amperage fuses that will fit in the same fuse slots. Using a higher powered fuse than necessary usually won’t be a problem, but if you accidentally put a 10amp fuse where a 30amp fuse should be, you’re going to blow the fuse extremely quickly.
See these two below exhibits to help identify fuses:
Where is my Chevy Silverado Fuse Box Located?
Silverado’s and Sierra’s, and pretty much most vehicles, will all have two fuse boxes. One will be located inside of the engine bay, and the second will be located in the driver side footwell.
On Silverado’s and Sierra’s the engine fuse box is located on the right side of the engine bay when facing it, close to the top right corner. See the below picture for the location on 1999-2006 trucks. Note that this is what it looks like with the fuse box cover off. When you open your hood, this will have a plastic covering over it which should pop off very easily.
The second fuse box is located within the driver-side dashboard. When you open up the driver door, the fuse box is located within the flat part of the dashboard that is directly facing you / meets directly with the door when closed. The panel that it sits under is the triangle-like shaped panel. You should be able to pop it out pretty easily by pulling from the bottom of it.
Diagnosing a Blown Fuse
Now that you’ve found the fuse boxes, how can you tell if a fuse is blown? The majority of fuses will be made of a colored, see-through plastic. When you look inside of the plastic, you’ll see a small metal connector piece. This is the piece that provides the amp transfer from the battery to the system. When the fuse becomes overloaded and breaks or blows the metal connector piece will actually break.
You’ll notice the metal inside is actually snapped in half. This is a safety measure to prevent the overloaded amps from being transferred to your electrical system. Instead, the fuse blows and prevents the excess amperage from being passed to your components.
Here is a picture of a good fuse vs. a bad one. It is worth noting that the internal metal connector will not always be “S” shaped like the one in this example. More commonly they will look like an “n” or a hill.
1999-2006 Chevy Silverado Fuse Box Diagram
Note this diagram is also applicable for GMT800 1999-2006 GMC Sierra’s as well. While the covers for the fuse boxes should have these diagrams on the inside of the them, these cars are getting old now so they might be hard to read or have worn away by now.