How to Hook Up a 4-Channel Amp

By Aaron Wein

Installing a 4-channel amplifier into your car can be a time-consuming and sometimes confusing task. There are many wires running from the amplifier that also need to be concealed for a clean installation. This requires careful planning on the part of the do-it-yourselfer, so make sure you have a few hours to complete the task. Although the install can last hours, once you've planned out your strategy it's a simple process.

Things You'll Need

  • 4-channel amplifier
  • Caulk
  • Caulking gun
  • Amplifier wiring kit
  • Electric driver
  • Monkey wrench

Setting Up the Amplifier

Step 1

Disconnect the negative terminal of the car battery for safety purposes and to prevent a short circuit.

Step 2

Mount the amplifier in a dry area with good ventilation. The amplifier heats up during operation, so it's good to install it in a cool area such as the trunk.

Step 3

Screw the amplifier in place to prevent it from jostling during driving by using an electric screwdriver, screwing it into the carpeting of your vehicle.

Making Speaker and RCA Connections

Step 1

Connect new speaker wire to your speakers that you wish to power with your amplifier. Be sure to match polarities during the whole installation process by matching positive leads with positives terminals and vice versa for negatives.

Step 2

Run the speaker wires to your amplifier and connect them to the proper channels. For instance, a front passenger speaker's wire will connect to the "Front Right" section of the amplifier. This step is important in order to achieve proper surround sound setup.

Step 3

Connect the RCA cable to the amplifier's RCA input. It should be labeled "RCA" or something similar.

Step 4

Pull out your car's head unit and connect the RCA cable to the head unit's proper RCA output and reinstall the head unit.

Connect the Power Wire

Step 1

Look for a hole underneath your dashboard that leads to the engine bay. This is where you'll need to run the power wire through to the battery in order to power your amplifier. You may need to cut a hole through your firewall using an X-Acto knife in order to reach the engine bay.

Step 2

Run the power wire through the hole and attach it to the positive lead of the battery.

Step 3

If you're power wire's fuse isn't already attached to the wire, attach it to the power wire being sure it's as close to the battery as possible. The fuse prevents the power wire from shorting out and burning, but it doesn't protect the portion that the battery is attached to. Most power wires come in sets of three: the portion that connects to the battery (usually a few inches long), the fuse, and the portion that attached to the amplifier (usually many feet long). Attach the fuse by plugging it into the portion that connects to the battery and plugging it into the other length of the cable.

Step 4

Connect the power wire plug-in to the amplifier. The amplifier's power input should be clearly labeled "Power" or something similar.

Step 5

Caulk the hole you used to run the power wire through and seal it.

Ground the Amplifier

Step 1

Connect the grounding wire to the amplifier to the input labeled "Ground."

Step 2

Locate a stable metal fixture on your vehicle such as a nut.

Step 3

Unscrew the nut and place the ground output underneath where the nut screws in; screw the nut over the grounding wire.

References & Resources