The lowest tones of music are best played through larger speakers such as subwoofers. The subs require a greater signal strength than the other speakers in the vehicle, so amplification is necessary to drive the subs to produce the expected level of performance. You can bypass the installation of an amplifier by choosing a powered-subwoofer. Powered-subs have built-in amps and can be connected directly to the vehicle's stereo.
Open the hood of the vehicle and loosen the bolts for each battery terminal with a wrench or pliers.
Remove the negative battery cable clamp from the negative battery post. Rest it away from the battery.
Place the amplifier wiring kit ring terminal against the positive battery lead post and tighten the positive cable clamp around it with the wrench. Remove the ring terminal fuse from the fuse holder compartment.
Plug the power supply cable into the ring terminal. Route the cable into the vehicle's cabin through the firewall. The cable will emerge in the footwell of the vehicle.
Run the cable from the footwell to the rear cargo area of the vehicle (or trunk for cars).
Remove the vehicle's stereo from the stereo dock in the dashboard. Consult the repair manual for exact procedures.
Unplug the stereo wiring from the rear panel of the stereo unit. Plug the wiring harness adapter lead connectors into the outlets on the stereo's rear panel.
Plug the stereo wiring from the vehicle into the corresponding lead connectors of the wiring harness adapter. Plug the signal and turn-on lead cable connectors into the wiring harness adapter. Consult the wiring harness adapter manual for proper connection locations. Some harnesses will be color-coded to show the appropriate connections.
Feed the signal and turn-on lead cables through the back of the vehicle's stereo dock and down to the floor of the vehicle. Be sure, if given the option in your particular vehicle, to choose for the cables to emerge on the passenger side of the vehicle.
Route the signal and turn-on lead cables to the rear of the vehicle, on the opposite side from the power cable. The power supply cable will emit interference that will affect the signal if run together.
Place the powered-sub in the trunk or rear cargo area of the vehicle.
Plug the power supply cable into the powered-subwoofer. Plug the signal cable and turn-on lead cable into the appropriately labeled outlets on the sub.
Connect the grounding wire from the amp wiring kit to the sub and a bolt or screw in the rear of the vehicle. Choose a bolt that is directly connected to the vehicle's frame for optimum grounding. Return to the battery.
Place the grounding cable clamp back around the negative battery lead post. Tighten the cable to the post with the wrench. Place the fuse into the fuse holder on the ring terminal and close the holder's lid. Close the vehicle's hood.
