How to Hook up the Wires to a Car Stereo

By Don Bowman

  • Overview

    When attempting to wire a car stereo, the first thing to understand is what the wires and connections are for in the back of the radio. All radios are similar and an understanding of one will prepare you to install any radio. The radio will have two power wires, one for memory and one for the main power. It will have two ground wires and six or eight speaker wires, depending on brand. The radio, if it is suitable for amplification, will have two or four plug-in connections marked audio out and one antennae connection.
    • Step 1

      Go to a stereo shop and get the right connector harness. This eliminates cutting wires and adding wire connectors and finding the proper stock speaker wires. These harness connectors are inexpensive; simply plug the radio harness in one side and the factory harness in the other. This also works if the factory speakers are to be replaced, as the factory speaker wire can still be used.
    • Step 2

      Look at the wires on the back of the radio and locate the yellow wire if a harness connector is not available. This wire is for the memory and must be hooked up to a continuous power source.


    • Step 3

      Hook the main power wire, which is usually red, to a switched source of power. If you do not see a red wire, check the wiring diagram for the radio---sometimes power wires are white. When the ignition is on the radio has power and with the switch off the radio is off.
    • Step 4

      Hook the two solid black wires to a good ground and make sure it is free of paint.
    • Step 5

      Notice the six or eight wires on the back. These are the speaker wires. The wires will be grouped in pairing colors, one gray wire with a second gray wire with a black stripe. The gray wire, for example, is the speaker wire positive and the second gray wire with a black stripe is the negative side. Use the diagram on the radio, if possible, to determine which wires are for the front and which are for the rear. If this can't be determined because there is no diagram on the radio then it is a good idea to have a separate speaker.
    • Step 6

      Connect the wire pairs one at a time to this speaker and determine which wires are the side, front or rear speaker wires. The plug-in connectors on the back are made to run a harness from them to the input of an amplifier. If these are used there is no need to hook up the speaker wires at the radio, just the power and memory and ground wires.
    • Skill: Moderate

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