How to install a USB port in my car to play my MP3 files

Updated April 09, 2017

Adding a USB port to your car stereo to play MP3 files on USB flash drives can be done in several ways. Professional installation is recommended, but if you do it yourself, follow the directions and safety precautions that accompany the unit. Installation steps will vary by car audio manufacturer and by make, model and year of the car. Want an easier solution? Purchase a wireless FM modulator with a USB port that plugs into the cigarette lighter receptacle and plays the audio through your car’s FM radio and speakers.

Replace your in-dash stereo system with a new one that has a USB port. Follow the specific instructions that come with the new unit. Disconnect the car battery first and remove the dash trim panel. Disconnect the wiring harness and antenna cable. Remove the old radio from the dash and install the mounting kit for the new stereo, if required. Connect the wiring harness of the new stereo system to the car’s factory wiring harness by crimping or soldering the wires together. Plug in the antenna cable and place the new stereo system into the dash opening. Test it by turning on the power and tuning in both AM and FM stations. Play a CD. Put a USB flash drive in the USB port and play a tune. If everything works, complete the installation by securing the radio/CD player in the dash and reinstalling parts of the dash trim panel that you removed earlier.

Use a vehicle-specific interface kit to add a USB port to the existing in-dash stereo system. First disconnect the car battery and remove the dash trim panel. Access the back of the radio/CD unit by unmounting the unit from the dash. Do not disconnect the wiring harness from the radio/CD unit. Locate the CD changer port and attach the vehicle-specific data cable of the USB interface unit to the CD changer port. Test what you’ve done so far by turning on the car stereo and using the CD/AUX button to switch to CD changer mode. Connect one end of the supplied USB cable to the interface and the other end to a USB flash drive loaded with music. Play a tune and verify that it plays through your car’s speakers. If the interface works, complete the installation by securing the USB interface in the dash, allowing enough room for the car stereo unit to fit. Run the USB cable to the inside of the glove box or to an available open space on the dash. Remount the radio/CD unit and reinstall the dash trim panel.

Play MP3s on a USB flash drive through your existing car radio and speakers using wireless FM modulator with a USB port. No need to remove the existing stereo system. Insert the 12v adaptor end of the FM modulator into the car’s cigarette lighter/auxiliary power receptacle. Insert a USB flash drive with MP3s into the USB port on the modulator. Tune your radio to one of the modulator’s preset FM frequencies and use the tuning wheel or button on the modulator to adjust the reception until you get static-free sound. You may need to try several of the preset frequencies to get the best reception and sound clarity. Some FM modulators with USB ports have controls for previous track, play/pause, next track and other features.


Be sure your new system is compatible with your make, model and year of car. Most online car audio sites have a wizard that will help you find compatible systems. Confirm that the new system will operate with steering wheel controls, if your car has that capability. You may need to purchase an adaptor. Some car stereo models have the USB port on the faceplate, while others may run the USB port to the glove box. If you have a “premium” sound system in your car, you may need to purchase a special adaptor or faceplate. If your system uses a security code, be sure you know the code before unplugging the radio. Ask your car audio retailer or online seller for help. Most offer technical assistance and additional installation tips.

Things You'll Need

  • Phillips or flat blade screwdriver
  • Panel tool/clip remover
  • Wire cutters
  • Wire stripper
  • Soldering iron
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Joan Greylord is a marketing communications and feature writer in Illinois. She has been writing professionally since 1980 for the health care industry and high-tech fields. Her articles have appeared in "The Southern Health Magazine," "SI Magazine," and "Cat Fancy Magazine." Greylord especially enjoys writing about new trends in health care and alternative medicine.