i am looking at installing a head unit in my car and on the list of what each wire is one of them says CAR RADIO SWITCHED 12V+. this is confusing me because also on the list i have a constant 12v+ which i got so do i need the switched 12v also? thanks

 

Yes, the constant is used to keep the settings and time in your stereo. The switched is what will actually turn your stereo on. It's triggered by the key, so when you start your car or turn the ignition to the accs position, it supplies power to your stereo, it's the main power for your stereo. If you haven't cut off the factory harness connector, which sounds like you have. But if you haven't, go down to your local best buy/wal-mart/whatever and get a adapter. It will let you hook up your stereo wires to it and then plug into the stock wireing for your car. Easy and your best bet.