2.5 I heard that I should run my power wire directly to my car's battery? Why should I bother, and how do I do it? [JSC]
For some components, like head units and equalizers, it's acceptable to use the stock wiring for power. However, amplifiers generally require large amounts of power, and accordingly will draw large amounts of current. The factory wiring in most cars is not designed to handle large amounts of current, and most wires have 10-20A fuses on them. Thus, you will almost always want to run the power line for your amplifier directly to the positive terminal of the battery. This could require drilling a hole through the car's firewall, or at least spending time hunting for an existing hole (the steering column is a good place to start looking). Always remember to place a fuse on your wire as near to the battery as possible! For various reasons, such as an accident or simple wear and tear, your wire's insulation may eventually crack, which could allow the conducting wire to make contact with the chassis of the car and short the battery through this wire, which could lead to a serious fire. The closer you place a fuse to the battery, the more protected you are. Also, when running wire through areas with sharp metal corners, it is a good idea to use rubber grommets to provide extra protection against tearing through your wire's insulation.