A. Test equipment needed, a 1.5 volt flash light battery and a meter for testing voltage.

First, with the ignition off. There will be one hot wire, it is constant +12 volts. If it is missing check fuses. This wire connects to the YELLOW wire on your aftermarket car stereos.

Second, turn ignition on, look for the wire with +12 volts, this is your switched power. If it is missing check fuses. This wire connects to the RED wire on your aftermarket car stereo.

Third, turn parking lights on, look for the wire with +12 volts. Most aftermarket stereo do not use this wire, cap it off or it connects to the Orange/Orange with white stripe wire on your aftermarket car stereo.
Forth, with the flash light battery and remaining wires, touch and hold one wire to one side of the battery. Touch each remaining wire, one at a time to the other end of the battery. When you hear a snap, pop or scratchy sound from one of the speakers, tie the two wires together - it is a matching pair for one speaker. Continue the process till the wires are all paired off. Depending on the number of speakers in your car, you should have one pair for each speaker. If you are unable to recognize any speaker wire pairs, you have a factory amplifier or you are missing speakers from the car.

Now, you may have several wires left on the cars wire harness. One maybe ground, one or two may be for illumination and/or dimmer control for back lights, one may be amplifier trigger, and one may be power antenna trigger. One of the biggest problems we see with hooking up an aftermarket stereo, is one of the illumination/dimmer wires is mistaken for ground. It is safest to cap all remaining car wires off and connect your ground wire from your aftermarket car stereo directly to metal. (Not all ground wires are BLACK).
If your factory car stereo system has an amplifier, this process does not apply. You will need to purchase the aftermarket "Amplifier Bypass" cable for these instructions to be applicable. In most cases, the aftermarket stereo you are installing has more power than the factory amplifier. You want to bypass the factory amplifier.
If you feel that wire color codes are necessary for installing your aftermarket car stereo, we suggest contacting your local dealership. We do not supply any further technical support other than the information we have posted. Thank you.