How to Add AUX to a Car Stereo

Car owners who would like to upgrade their stock stereo system have several options. Add an AUX line-in to the vehicle's car stereo to connect external stereo devices, such as an iPod or satellite radio receiver. To establish the auxiliary input, connect the FM modulator to the stereo head unit. The FM modulator serves as an input for your external devices through a closed circuit for better audio quality.

Things You'll Need

• Adjustable wrench
• Vehicle repair manual
• Wiring harness adapter
• FM modulator

Instructions

1. Pull the hood release lever under the driver's side dashboard. Move to the front of the vehicle. Lift the hood. Locate the negative battery cable connection to the negative battery terminal. Remove the cover from the terminal. Loosen the bolt that holds the cable to the terminal with a wrench. Lift the cable from the battery and set it aside. Return to the inside of the vehicle.

2. Remove the stereo from the dashboard stereo dock. This process may require the removal of dash panels from the dashboard. Consult the vehicle repair manual (or shop manual) for instructions specific to the vehicle's make and model.

3. Disconnect the stereo and antenna wiring from the back of the stock stereo. Plug the stereo wiring into the wiring harness adapter. The adapter allows you to tap into the signal and power input for the stereo as needed for the AUX-in (via the FM modulator).

4. Plug the FM modulator lead connectors into the wiring harness adapter leads. Plug the wiring harness adapter into the corresponding outlets on the back of the stereo.

5. Plug the vehicle's antenna cable lead into the antenna input on the FM modulator. Plug the FM modulator's antenna lead into the stereo's antenna input (commonly on the lower left corner of the stereo's rear panel of outlets).

6. Feed the input cable for the FM modulator into the glove compartment adjacent to the stereo dock. The input serves as a connection point for any device you wish to connect to the stereo. Place the main box of the FM modulator into the back of the stereo dock.

7. Slide the stereo back into the vehicle's stereo mounting dock. Replace any screws and paneling removed to extract the stereo unit. Consult the shop manual for exact procedures. Return to the vehicle's battery.

8. Place the negative battery cable clamp back onto the negative battery terminal. Tighten the cable to the battery terminal with the wrench. Replace the cover over the negative battery terminal. Close the vehicle's hood.

Tips & Warnings

• Choose "AUX" on the stereo's menu to play content from devices connected to the FM modulator's input. You also can tune to the frequency on the FM modulator itself to play the content through a closed-circuit.

References

• Crutchfield: FM Modulators; Peripherals Installation Guide