The ACC wire is used to power devices that are not essential for the operation of the vehicle, such as the radio, power windows, and air conditioning. When the ignition is turned off, the ACC wire loses power, and these devices are turned off.
The ACC wire can also be used to power aftermarket devices, such as GPS units and phone chargers. To do this, you will need to connect the device's power wire to the ACC wire. You can also use a power outlet adapter that plugs into the vehicle's cigarette lighter socket.
It is important to note that the ACC wire is not always live. On some vehicles, the ACC wire only provides power when the ignition is turned to the "On" position. On other vehicles, the ACC wire provides power even when the ignition is turned to the "Accessory" position.
If you are not sure whether the ACC wire on your vehicle is live when the ignition is turned to the "Accessory" position, you can use a multimeter to test the wire. To do this, set the multimeter to DC volts and connect the positive probe to the ACC wire and the negative probe to the vehicle's ground. If the multimeter reads 12 volts, then the ACC wire is live.
