Where should I ground my amp?

Your ground wire should be of the same gauge as your power wire and must make direct contact with the body of the car. Look for an existing bolt or screw that makes contact with the car body near the amp. Remove the bolt or screw, and scrape away any paint or grime.

A star washer will help your ground wire maintain solid contact with the car body. Use a ring terminal on the end of the ground wire, to keep it securely fastened to the bolt or screw.

If you can't find a convenient ground screw or bolt, drill a hole for one. Be careful not to drill into the gas tank, a gas line, or a brake line.

If you're grounding multiple components, try to ground each one separately, with about a half-inch of space between each of the grounding points. If you'd rather use a single bolt, place the ground for the most current-hungry component (probably the biggest amp) closest to the body of the car. Put the ground for the component that draws the least current (probably the electronic crossover) on top.