This is actually a good question. However, what you see is actually a piezo speaker, not a buzzer. While speakers only require two wires, most motherboards have four pins where the speaker header plugs. Usually, the extra wires are an extra ground and perhaps 4.5 volts, if not 12 volts. It is possible that the extra pins were intended for the front panel lights.
Or, it is possible that manufacturers once left open the possibility of adding an audio amplifier. You have everything you need there for an amplifier. You have positive and negative signal wires as well as positive and negative direct current.
Wires and a motherboard and a battery
The speaker wires on a 2005 Avalanche are white. Most automobile manufacturers use white wires for the speaker wires. After market speaker wires are usually red or blue in color.
I'd check the speaker wires although my first suspicion would be the old, stock speakers. Do they rattle or emit no sound at all?
Other things that speaker wires can be used for is power transmission. Speaker wires have negative and positive glued together in the insulation, it isn't intended for this purpose but can work.
It powers the wires, thus powering the light or sound buzzer.
To find your speaker wires, check your owners manual. You should find a diagram with the location and color of your speaker wires.
no
d
1. Battery 2. Wires 3. light bulb, buzzer
the buzzer is located under the dashboard on the drivers side, it looks like a little white box with a grey plug comming out of it with about 5 wires or so.
Wires And A Amplifiers
Ussually the speaker wires coming out of the back of the radio itself are green, purple, white, and grey.