Installing Aux Audio Input: Wiring the Sound System

What You'll Need
Owner's manual with guide for speakers and dash
Car stereo wire harness kitNew head unit (radio and CD)
9-volt battery
Box cutter knife
Wire cutters
Wire strippers
Screwdriver set
Wiring kit for amplifier
14-gauge wire for subwoofer (optional)
Electrical tape

Adding aux audio to your car takes attention to detail but is a doable task for you and a friend on a weekend afternoon. Follow the steps outlined below to wire this powerful sound system into your vehicle.

Step 1: Identify All Parts of Your New System

Ensure you can locate and find the wiring for the head unit, which includes the radio and CD player, the existing speakers, the amplifier and the subwoofer, if you are going to install one.

Step 2: Disconnect Electrical Power from the Battery

Detach the negative terminal cable from your car battery. Never do electrical work on your car with the battery connected.

Step 3: Remove Old Speakers

Unscrew the speaker cover panels and take out the old speaker by undoing the screws holding it into the body of the car. Take off the wire connectors from the old speakers.

Step 4: Find Speaker Wires and Connect to New Speakers

Cut the old speaker wires off, strip 1/2 inch of these speaker wire ends, and strip the same length off your new speaker wires. Twist the old and new speaker wires together and seal with electrical tape. Attach the negative (black) and positive (white) wire connectors to the new speakers. Affix the new speakers into the car body with the screws provided. Put the speaker covers back on after you do final sound checks.

Step 5: Remove Old Head Unit

Carefully remove the dash cover according to the owner's manual and unscrew the old head unit. Attach the car wire harness from the old head unit to your new one and also attach the antenna cable and the speaker wires. Check that you have fastened the negative and positive wires together correctly. Next, attach the amplifier to the head unit.

Step 6: Attach the Amplifier Wiring

Connect the red positive amplifier wiring to the positive terminal of the 9-volt battery with the O-ring in the wiring kit. Connect it to the head unit before placing it in the trunk or rear of your car.

Step 7: Connect the Subwoofer

Place the subwoofer in the rear or trunk and attach it to the amplifier to keep it in place. Attach the speaker wires to the left and right terminals for the correct channels on the amplifier and the subwoofer.

Step 8: Install the Head Unit into the Dash

Check that all connections are secure before placing and securing the head unit in the dashboard. Insert the head unit into the dash, screw it in, and replace the dash cover. Reconnect the power to the main car battery and turn on the head unit.

Step 9: Final Checks

Listen to each speaker in turn to ensure they work properly. Turn the controls for the amp and subwoofer to check they are controlling the sound output. Finish fastening the speakers into their compartments and replace the speaker cover panels. Gather and put away all tools, and you're ready to go.