Can I test head unit at home?

Question

I forgot my cd in the player when I took it out and already installed new headunit.

Answer 1

Yes, you can. You can actually get the radio to power on if you touch the power wire(red) to the positive of the battery and the ground wire(black) to the negative side on the battery.  once you do that you'll have power to the CD player to get your CD out.

Answer 2

If the head unit is aftermarket you can connect the red and yellow wires to the positive battery post, the black wire to the negative post and press eject. Get someone to help by holding the wires while you hold the radio and press the button. It won't shock you.

Answer 3

Find someone who knows their electronics and have them wire the old head unit to a 12v battery