A Guide to Wiring an Aux Jack

An aux jack can be wired into a car stereo system for use in playing an mp3 player, a portable CD player, or other device. Many of today's newer car stereo systems have an aux jack already installed so that they are more versatile. If the car stereo in your vehicle does not have an aux jack included, you will need to have one installed. Wiring in an aux jack is an easy project for any do-it-yourself mechanic.

Step 1: Determine Aux Jack That Is Needed

Before you purchase an aux jack for your vehicle, you should make sure it is the one that you want to use. Some aux jacks have multiple inlets for playing different types of media and size of jacks. Check into the various types to make sure that you will not have to change it in the future.

Step 2: Determine Location for Aux Jack

Most of the time the aux jack is close to the stereo. This means that you will not have to use a lot of wire in the process. Most vehicles have a small space in between the radio and the heater that can be used as a spot. However, mounting under the dash is also a good place. Choose the location before moving on.

Step 3: Disconnect Battery Cable

Remove both of the battery cables to make sure that there is no power and that there is no potential for crossing the wires together.

Step 4: Remove Dash

You will need to have some access to the rear of the stereo system in the vehicle now. To do this, removing the dashboard is necessary. Go around the dash and remove the retaining screws. Make sure to get them all and carefully pry the dash off.

Step 5: Remove Stereo

Unscrew the retaining screws that are holding the stereo in place and slide it out. Remove the wiring harness and place the stereo aside.

Step 6: Install Aux Jack

Use a drill and mount the auxiliary jack in the area where you determined it should go. You may need to drill a hole in order to feed the wires through to the rear of the dash.

Step 7: Connect Wiring to Jack

When you purchased the aux jack, there would have been a wiring harness already included. If not, then purchase a harness that is compatible with the jack and stereo. Connect the wires to the terminals on the jack. Use a screwdriver to tighten the terminal screws.

Step 8: Connect Wiring to Stereo Wires

Feed the wires up through the rear of the dash until you can see them where the stereo is located. Pull the wires out so you can work on both of them at the same time. Strip back the insulation 3/4 inches on the wires from the jack. Cut the matching color wires on the stereo system harness and peel back the insulation on them also. Use the wire connectors and shrink the insulation around the new wires. Connect all the wire together through the terminal.

Step 9: Replace Items and Try Aux Jack

Once the connections are made, slide the stereo back in and connect to the wiring harness. Replace the dashboard and battery cables. Test out the aux jack to make sure it works.