How to Wire Up a Car Radio Power Booster

by David Lipscomb Google
    Car amplifiers boost stereo signals for increased volume and dynamics.

    Car amplifiers boost stereo signals for increased volume and dynamics.

    Matthew Peyton/Getty Images Entertainment/Getty Images

    Using larger power supplies and pulling more voltage from the vehicle's charging system, amplifiers make any car stereo sound better by supplying far more wattage to speakers than the in-dash radio can provide. Following proven installation methods ensures the best performance for your amplifier, satisfies the voltage requirements for the device and keeps the system safe and reliable.

    Radio Connections

    Step 1

    Pop the hood and disconnect the black negative wire on the vehicle's battery using the socket wrench and the correct insert. Get inside the vehicle and set the parking brake.

    Step 2

    Consult the vehicle schematic to locate the various screws and clips securing the radio and surrounding trim.

    Step 3

    Remove the screws securing the radio trim with the appropriate screwdriver. Gently yet firmly pull away the trim, revealing the radio brackets.

    Step 4

    Unscrew the screws securing the radio into the dash. Set these aside in a cup holder or bag for later use.

    Step 5

    Pull the radio free from the dash cavity. Snap a T-tap connector over the ACC (accessory) wire on the radio's wire harness.

    Step 6

    Plug the RCA cables into the RCA pre-out jacks on the back of the radio. Lead these wires through the dash cavity behind the radio and out under the glove box.

    Step 7

    Snip a length of primary wire long enough to reach from behind the radio to the intended amplifier mounting location.

    Step 8

    Strip 1/2 inch of insulation from one end of the primary wire. Crimp the male spade connector half of the T-tap assembly to this end of the wire. Slide the prong into the slot on the other T-tap component. Drop the wire behind the cavity alongside the RCA cables.

    Power Wiring

    Step 1

    Cut a 12-inch-long piece of power and ground wire. Cut another length of power wire long enough to reach from the vehicle's battery to the amplifier mounting location.

    Step 2

    Strip 1 inch of insulation from both ends of the short power wire. Crimp a ring terminal to one end of this wire.

    Step 3

    Slide the other end of the short power wire into one end of the fuse holder. Secure the wire with the holder's set screw and the appropriate screwdriver.

    Step 4

    Strip 1 inch of insulation from one end of the long power wire. Connect this end to the other end of the fuse holder.

    Step 5

    Locate a wire bundle leading from the engine compartment into the vehicle's cabin. Push the other end of the power wire through this grommet until it appears under the dash.

    Step 6

    Pop up the door sill trim closest to the where the power wire enters the cabin. Push the power wire through the vehicle's wire channel until you reach the mounting location of the amplifier.

    Step 7

    Route the RCA cables down the other side the vehicle in the wire channel opposite the channel with the power wire, helping to resist induced noise.

    Ground Connections

    Step 1

    Remove a dime-sized section of paint within 12 inches of the amplifier's mounting location using the cutting tool and sanding disc. Wear goggles in case a piece of the disc breaks off at high speed.

    Step 2

    Continue sanding until the metal is bright and shiny. Strip 1 inch of insulation from both ends of the ground wire you cut earlier. Crimp a ring terminal to one end of this wire.

    Step 3

    Center the ring terminal over the sanded section of sheet metal and star washer. This washer maintains constant tension on the ring terminal, preventing it from loosening from vibration. Secure the ground wire by driving a self-tapping screw through the center of the ring terminal into the chassis.

    Final Connections

    Step 1

    Strip 1 inch of insulation from the power, ground and remote leads.

    Step 2

    Slide the power wire into the "B+" or "+12v" terminal on the amplifier. Connect the ground wire into the "GND" terminal. Slip the remote line into the "REM" terminal. Secure each with the right screwdriver.

    Step 3

    Push the RCA cables into the RCA inputs on the amp, matching red to red and white to white.

    Step 4

    Slide the fuse into the fuse holder. Replace the cover on the holder. Reconnect the negative wire to the battery.

    Tips

    • Covering the power wire with flexible loom under the hood and to the amplifier blends it with stock wiring. This not only protects the wire but enhances security by not making its presence obvious.

    Warnings

    • Never route power wires through door jambs or any places where they may be stepped on or pinched.
    • Do not ground an amplifier to a seat belt bolt or welded spot on the chassis. These locations do not provide suitable continuity for the electrical connection, potentially causing engine noise to manifest and general system instability.

    Required Items

    • Socket wrench and insert
    • Vehicle schematic
    • Screwdrivers, Phillips, Allen and Torx
    • 16 gauge stranded primary wire
    • T-tap connectors
    • RCA cables
    • Power and ground wire
    • Crimp tool
    • Crimp-on ring terminals
    • Fuse and fuse holder
    • Cutting tool with sanding disc
    • Safety goggles
    • Drill with Phillips bit attachment
    • Star washer
    • Self-tapping Phillips screw

    About the Author

    David Lipscomb is a professional writer and public relations practitioner. Lipscomb brings more than a decade of experience in the consumer electronics and advertising industries. Lipscomb holds a degree in public relations from Webster University.

    Photo Credits

    • Matthew Peyton/Getty Images Entertainment/Getty Images