1) Understand the basics of all car stereo systems. A car stereo system consists of 4 main components and the wiring that connects them. These are the head unit, the main speakers, optional amplifiers and the subwoofers, which are also optional but generally considered a necessary part of any good system.
2) Know that the core of any car stereo is the head unit, which is the cassette or CD player that goes in the dash. All the other components are connected to the head unit by at least one pair of wires.
3) Know about car speakers. The main speakers are usually 2 in the front and 2 in the back, although with what are known as component speakers, each speaker is broken down into two speakers: one for the highs and one for the bass. Each speaker or speaker set (known as a channel) connects to the head unit via a pair of wires. Generally if you are installing a new head unit you want to install new speakers.
4) Know about amplifiers. Amplifiers provide extra power to your speakers and/or extra channels of power for additional speakers. The most common use for an amplifier (amp) is to power subwoofers. The amp connects to your head unit via an RCA cable and often a "remote on" wire, and also connects directly to your car battery through a fused "hot" wire and to the car's chassis with a short ground wire. This article assumes the use of a single amplifier connected to a pair of subwoofers. If you do not have these components simply ignore the steps specific to the amp, doing so will not affect the rest of your installation.
5) Know about subwoofers. Subwoofers are part of any good stereo system. They provide the deep bass that small speakers cannot achieve. Subwoofers are connected to the amplifier which can usually be mounted right to the subwoofer box. If you do not have subwoofers you can simply ignore the steps specific to them.
FOR more help click on this link directly
This will help. Thanks please
keep updated.please do rate the solution positively .thank you for