How to Connect Car Audio Systems

Aftermarket audio systems are popular among drivers who are looking to improve the sound quality in their cars. The difficulty of connecting a new audio system can vary, depending on if you are installing just a new stereo and/or speakers and if the stereo requires an outside amplifier. It can also vary depending on your type of vehicle.

Things You'll Need

• Car stereo
• Amplifier (optional)
• Speakers (optional)
• Screwdriver
• Crimping or soldering kit
• RCA cables

Instructions

Installation

1. Disconnect the car's negative battery cable before working on any part of the stereo system. Also, remove the old factory stereo from the car. Pry off the trim panels from the instrument panel--this varies with each car, but often requires a flat-bladed tool. Remove mounting screws/bolts. Pull the stereo out of the instrument panel and disconnect its wiring harness.

2. Install new speakers if you have them. Aftermarket speakers often aren't designed specifically for your car; you must find a place in your car to install them, like behind the rear seats. Cut holes in the upholstery to fit the speakers into; larger subwoofers go in the trunk.

3. Route the wires for the speakers to the stereo in the front. You can often run the wires through the crack in between the back seat and wall, along the floorboard and through an available hole in the firewall. The exact method for routing wires can vary depending on the type of vehicle; consulting an expert is recommended.

4. Connect the stereo or your aftermarket amplifier (if you are using one) to the speakers. If the speakers are wired to an electrical connector that will connect to the stereo, simply plug the connector in. Otherwise, you must connect the wires personally by crimping or soldering the wires together (see Section 2).

5. Connect the amplifier to the stereo if they are separate. These are usually connected by RCA cables, the two-pronged cables with the red and white plugs. The stereo is then mounted inside the dashboard, through either its or the car's mounting bracket--possibly a combination of both. An amplifier needs a secure storage area, like underneath a seat.

Wiring Guide

1. Decide how to connect the wires together; there are two main options, crimping or soldering. Crimping involves twisting the wires together as they line up side by side, inserting their leads into a crimping cap and tightening the cap with a crimping tool. To solder them, twist the leads together as they point to one another, apply the soldering gun with the solder touching the wire and insulate the leads with heat-shrinking tubes.

2. Connect the speaker wires if necessary. Generally, the gray wires go to the right front speaker, the white wires to the left front speaker, purple to the right rear and green to the left rear. The cables with the black stripe go to the negative leads and the plain ones to the positive. The orange wire is for illumination.

3. Connect the power wires. The red wire is for switched power and connects to the wiring harness on the car starter. The yellow wire is for constant power and is mounted under the battery's positive terminal. If you're using a stereo and amplifier, both connect to the battery but only the stereo connects to the starter. Connect the stereo's switch wire (usually blue) to the amplifier.

4. Ground the solid black cable. Mount it under a screw on the chassis or another metal ground.

5. Connect the lead for the car's antenna to the stereo.

References

• How to Install Your Own Car Stereo System
• Crutchfield