If you can, do this indoors. Wiring a sub, amp, and head unit can take quite a bit of time and you’ll have to have quick access to a lot of tools. Doing this indoors will make it easier to stay cool and keep track of things.
Look for a positive (+) and negative (-) sign on the battery to distinguish between the positive and negative terminals. The positive terminal usually has a red cover as well. You may need a socket wrench extender to reach the bolt on the terminal.
The power wire or cable is used to power your amplifier. It used electricity from the battery to turn the amp on and off. Power cables for vehicle audio systems are usually red.
The firewall refers to the piece of the frame that separates the engine compartments from the interior of the vehicle. It is called a firewall because it is designed to stop a fire if one starts in your engine. Make sure that you don’t cut any of your other wires. On some vehicles, there will be a cover or plastic wring around the opening where your wires run. If this is the case, either remove the cap or push your wires down a little bit to make room for the power cable.
You can use a line pulling grip or drop mesh grip if you have one, but most DIY enthusiasts don’t have wire running tools. It’s not worth getting them for 1–2 ft (0. 30–0. 61 m) of cable running. If you have a really stiff power cable, you can skip this step and try to thread it through the firewall by hand.
If your car is newer, the wires may be hidden behind the frame of your vehicle. If this is the case, you’ll need to find a spot near the glovebox—either underneath or inside—where you can drill a hole to feed the wire into the vehicle.
A fuse holder will provide your audio system with a separate fuse. This will keep the system safe if you ever experience electrical problems with your vehicle. Most fuse holders have a clip that will attach it to the trim under the windshield.
Place 1 zip tie every 2–4 inches (5. 1–10. 2 cm) to ensure that the cable doesn’t develop any slack. If the wires are well hidden or you drive a compact vehicle, you may have a little trouble reaching these cables. If you have a cable cover or concealer with your audio wiring kit, feel free to follow those directions instead.
You may need to drill a hole to access your trunk. It really depends on your specific vehicle’s make and model. If you drive a truck or don’t have a trunk, you can place the subwoofer under the front seat if there’s room. Some vehicles have a plastic slot where you can thread a wire into the trunk.
The head unit refers to the box where your radio dials and volume controls are. The wire harness is the small set of slots that bring all of your individual wires into the right slots on your head unit. Set any knobs or screws aside in a safe place so that you don’t lose them when it comes time to rebuild your dashboard. You usually start on the bottom of the dashboard where your cup holders or stick shift are.
This process depends entirely on your vehicle’s make and model as well as your audio wiring kit’s instructions. Use a zip tie to tighten bundles of cords together and make things easier. Cap any exposed wires with small pig tails by trimming them with wire cutters. Twist the pig tail on top of the exposed wire until it catches.
Some single-din head units come with a slot for a line converter directly underneath it. You probably need to use RCA cables to connect the head unit to the line out converter. You may need to plug a cable into the output port on the head unit and run it into the input port on the line out converter.
Hide the cable under the cases between the doors and seats or simply slide it under the floor mats. Leave the blue cord next to the red power cord.
If you ever smell something burning near your subwoofer when you use your new audio system, check the grounding wire. You cannot attach the wire to a painted surface. Use sandpaper to remove paint from a small section of metal if you need to.
On some audio systems, you’ll only need to connect the blue cable. On other systems, you’ll need to run RCA cables as well. Sometimes, all 3 of these cables are bundled together.
If the power cord opening on the amp is a small round knob, try unscrewing the cap and looping the cable over the screw. Then, tighten the cap over the loop to set it in place.
If the head unit doesn’t turn on, check the cable connections in the wire harness. If the audio sounds distorted, check your line out converter to make sure that your connections are clean. If you don’t hear anything, check the amplifier to see if it’s getting power from the battery.
