Car stereos require 12V DC power, so they cannot be plugged directly into home electrical sockets. You will need to convert the AC power from your wall socket into DC power to use a car stereo in your home. If you have an old ATX computer power supply laying around, or you can purchase one inexpensively, it is fairly easy to convert it to power your car stereo in your home.
Unplug the ATX power supply completely and leave it for at least four hours before continuing. Power supplies can retain charge after unplugged, creating a risk of electric shock.
Locate the largest bundle of wires coming out of the power supply, which should all be attached to a large, plastic, rectangular connector. Cut and strip the green wire and the nearest black wire, and connect the two by twisting them together and applying a wire nut. This completes the circuit, ensuring that the power supply will run when plugged in.
Cut and strip any yellow wire coming out of the power supply and the nearest black wire. Yellow wires provide 12V power and the black wire completes the circuit.
Connect the yellow wire to the 12V constant wire coming out of your car stereo and the black wire to the ground wire using twist caps. You may need to consult the manual or the manufacturer to find the correct colour for these two wires.
Plug in the power supply and flip the switch on the back of the power supply to the "On" position if there is one. Press power on the car stereo to test that it is working.
Use the RCA outputs from your car stereo to connect it to a set of speakers or a stereo unit for sound output.
You can bundle all the unused wires together to keep them out of the way when finished.
Do not open up the ATX power supply, as there is a risk of electric shock.