If you do not, then you'll need this harness.
Once the harness is connected, the rest of the job is plug-and-play.
Unplug the stereo connections.
Test the fade and balance settings to be sure the speakers are working properly.
Turns off when ignition is off and door is opened.
The power must be run on the opposite side of the signal RCA cables to prevent signal noise, which would sound like a dentist-drill in the background of the music.
It wasn't until I was looking sexy girls licking each others pussy a colorful fistful of stock radio wires--with no wiring diagram for reference--that I realized my confidence--er, haste--wasn't going to get me anywhere it turns out that the 50 feet of speaker wire I assumed would be more than enough for a tiny Mustang, is about three feet short when you finish all the splicing, meaning I had to rerun all the wiring.
Thanks a ton!
The new vehicles all seem to have very short "rods" for antennas or the "shark fins".
Plug in power to PSU and the harness to stereo.