How to Test a Car Stereo With a Variable Power Supply

Written by blaze johnson Google
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How to Test a Car Stereo With a Variable Power Supply
Use a DC power supply to test your car audio equipment. (power supply image by sasha from

Installing a car stereo into a vehicle can be a significant undertaking depending on the application. It can be disheartening to install a car stereo into your vehicle only to find out the unit does not work or has operational defects. Having a variable power supply on hand that has the capability to produce between 12 and 14.4 volts of DC power will allow you to test the car stereo before installing it in your vehicle.

Skill level:

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Things you need

  • Car stereo
  • Variable power supply
  • Speaker wire
  • Spare audio speaker
  • Wire strippers
  • Paper clip

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  1. 1

    Set your car stereo, audio speaker, speaker wire, wire strippers and power supply on a suitable table or workbench. Plug in the car stereo's wiring harness into the back of the stereo unit. Twist the red continuous power wire and the yellow "switched" wire of the car stereo harness together. Use wire strippers to remove about 1/4-inch of insulation from the end of the wires if needed.

  2. 2

    Connect the twisted together the red and yellow wires of the car stereo harness to the positive (red +) terminal of the power supply. Connect the black wire from the car stereo harness to the negative (black -) power supply terminal. Set the variable power supply's voltage between 12 and 14 volts DC power and plug it into a nearby wall outlet (refer to your particular power supply's operation manual for setting the voltage).

  3. 3

    Hook a small length of speaker wire to the audio speaker's negative and positive terminal leads. Connect the other end of the speaker wire to the corresponding negative and positive speaker wire connections on the car stereo harness for the left front speaker. If the speaker leads on your wiring harness are not clearly marked, refer to your car stereo's installation guide to find out which leads you need to use (certain car stereos have the harness wiring diagram printed on top if the metal chassis).

  4. 4

    Insert a straightened paper clip into the antenna port located on the back of the stereo unit so you will have a makeshift antenna while testing. Turn on your car stereo according to the operation guide that came with the unit. Search for available radio stations in your area to test your speakers or insert a test CD if your stereo came equipped with a CD player.

  5. 5

    Listen for clear sound coming out of the test speaker. Turn off the car stereo, unhook the test speaker from the front left speaker leads of the harness. Test the remaining speaker channels by hooking up the test speaker to the appropriate harness leads (refer to the harness wiring diagram in your documentation for the proper speaker lead connections).

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