If you plan to install a subwoofer in your vehicle, you need to first connect the audio system to an amplifier. This procedure involves disassembling the instrument panel and running various cables from the head of the vehicle to the subwoofer in the trunk or under the front seat. It won't necessarily be difficult, but it can take a long time, so be sure to set aside a few hours to build the system. Generally, the system runs on power from the vehicle battery that powers the amplifier and the line converter converts the signal from your head unit to the amplifier. You may need to purchase additional speaker cables or RCA cables outside of the wiring kit.
Steps
Method 1 of 3: Extend Cables to Battery
Step 1. Turn off the vehicle and raise the hood
Please do not put the keys in the ignition as the vehicle cannot be running when you extend the power cord and connect the main unit, amplifier and subwoofer. Press the button or pull the lever of the vehicle to open the engine hood. Raise the hood and lock it in place.
If possible, you should do this procedure indoors. Wiring a subwoofer, amplifier, and head unit can take a long time and you should have easy access to many tools. Doing it indoors will make it easier to keep it cool and keep track of things
Step 2. Disconnect the negative terminal of the vehicle battery
Pry the cover off the negative terminal to release it. Use a socket wrench to unscrew the bolt on the terminal by turning it counterclockwise. Remove the nut and pull the wire that connects the terminal to the rest of the vehicle and bend it away from the battery.
- Look for a positive (+) and a negative (-) sign on the battery to distinguish between the two terminals. Usually the positive terminal also has a red cover.
- You will likely need a socket wrench extender to reach the bolt on the terminal.
Warning:
If you unscrew the positive battery first, you could end up shorting if you use a metal wrench. Open the negative terminal first to make sure you don't damage anything.
Step 3. Connect an electrical wire to the positive terminal of the vehicle's battery
Open the cover and unscrew the bolt from the positive terminal. With the bolt removed, slide the open loop of the electrical wire over the positive terminal screw. Slide the bolt over the top of the bolt so that the loop of the electrical wire is located between the bolt and the base of the terminal. Replace the bolt with a socket wrench to secure the loop to the battery.
- The electrical cord is used to power the amplifier. This item uses battery electricity to turn the amplifier on and off.
- The electrical wires for vehicle audio systems are usually red.
Step 4. Drill a hole in the rubber next to the firewall to pass the electrical cable
Use a small knife to poke a hole right next to the opening where all the other cables enter the interior of the vehicle. In most vehicles, the cables run into the glove compartment on the opposite side of the engine. If the opening is sealed, poke a hole in the firewall with a small knife.
- Firewall refers to the part 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 fires that start in the engine.
- Make sure you don't cut any of the other wires.
- On some vehicles, there will be a cover or plastic around the opening where the cables run. If this is the case, you should remove the cover or push the wires down a bit to make room for the power cord.
Step 5. Unroll a wire hanger to insert the wire
You can do this by hand or use a wire cutter to hold the hook and unscrew the neck. Stretch the hanger until it is a single straight piece of wire. Roll the end into a small circle, and thread the free end of the electrical cord into it. Once the power cord extends through the hook, you should squeeze it so that it closes around the cord.
- You can use a line pull ring if you have one, but most DIY enthusiasts don't have tools to extend cables as they are not worth getting them to extend just 1 to 2 feet (30 to 60 cm) of cable. cable.
- If you have a very stiff electrical cable, you can skip this step and try to thread it through the firewall by hand.
Step 6. Slide the electrical cable through the firewall with the hanger
Use the hanger to slide the electrical cord through the hole you made. Slide the cable until you reach the glove compartment (or the opening below it) where the cables enter the interior of the vehicle. Open the passenger side door and look for the cable from inside. Pull it up and unhook the hanger.
If the car is modern, the cables may be hidden behind the frame. If this is the case, you should find a point near the glove compartment (either underneath or inside) where you can drill a hole to feed the cable into the vehicle
Step 7. Install the fuse holder by cutting the wire and mounting it close to the motor
If your audio system comes with a fuse holder, you should hold and expose the power cord 2 to 12 inches (5 to 30 cm) from the battery terminal. Use wire cutters to cut the wire where you want to install the fuse holder and strip the plastic sheathing from each end with the smallest opening at the end of the pliers. Slide each exposed section into the fuse holder opening and tighten the slots with an Allen wrench or socket wrench.
- A fuse holder will provide the 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 attaches them to the trim under the windshield.
Step 8. Mount the cable under the windshield with zip ties
Once you have fully pulled the electrical cable, it should be removed from the middle of the engine components. Lift the cable near the battery to the edge and look for the other cables that extend into the glove compartment. Use zip ties to tie the electrical cable to the other cables.
- Attach 1 zip tie every 2 to 4 inches (5 to 10 cm) to make sure the cable doesn't loosen.
- If the cables are well hidden or you are driving a compact vehicle, you may have a slight problem reaching these cables.
- If your audio wiring kit comes with a cable cover or corrector, feel free to follow those instructions.
Step 9. Hide the electrical cord along the floor to place it at the rear of the vehicle
Slip the power cord under the plastic covers between the passenger side doors and the seats or hide it under the floor mats. Run the cable to the rear of the vehicle or into the trunk so that you can connect it to the amplifier.
- You will likely need to drill a hole to access the trunk. This detail will really depend on the make and model of your specific vehicle.
- If you're driving a truck or your vehicle doesn'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 run a cable into the trunk.
Method 2 of 3: Mount the main unit
Step 1. Disassemble the center console to remove the factory head unit
Each head unit, center console, and removal process is different depending on the make and model of the vehicle. Check your instruction manual to see how you are supposed to remove the instrument panel to access the factory head unit. Levers are usually used to remove the covers after unscrewing the handles and screws from the center console. Once the factory main unit is exposed, slide or unscrew it before pressing the release clip to remove the wire harness.
- The main unit refers to the box where the radio dials and volume controls are located. The wire harness is the small set of slots that lead all the individual cables to the correct slots on the main unit.
- Set the handles or screws aside in a safe place so you won't lose them when it's time to rebuild the instrument panel.
- Generally, you should start at the bottom of the instrument panel, where the cup holders or gear stick are located.
Step 2. Match the colors of each wire on the new head unit
Depending on the audio system, you will need to connect a new head unit to the old wiring harness or a new harness to the existing one. Slide the new head unit directly into the wire harness while matching the corresponding colors or use a wire stripper to expose the wires in each corresponding pair and bend the exposed portion to tighten. Slide each set of exposed wires into a splice connector and use a crimping tool to push the wire into place.
- This process will depend entirely on the make and model of the vehicle, as well as the instructions for the audio wiring kit.
- Use a zip tie to tighten bundles of cables to make things easier.
- Cover exposed wires with small female connector wires by trimming them with wire cutters. Bend the female connector cable over the exposed wire until it snaps.
Tip:
Run a new speaker wire to the wiring harness if you plan to install new speakers. If you plan to install new speakers, this would be a good time to install a new speaker cable from the main unit to the line converter.
Step 3. Connect the line converter to the main unit
The subwoofer and amplifier operate on a different voltage than the speakers and the main unit. To compensate for this, connect a line converter to the main unit by connecting the left and right channel of the converter to the left and right channel of the main unit with RCA cables. Connect the other cables as indicated in the instruction manual for the audio system.
- Some single DIN head units come with a slot for a line converter located directly below.
- You will probably need to use RCA cables to connect the head unit to the line converter.
- You may need to plug a cable into the output port of the main unit and extend it into the input port of the line converter.
Step 4. Extend the blue wire to the amplifier on the opposite side of the vehicle
The line converter comes with a blue connection cable. This cable transmits information from the line converter to the amplifier. Run the cable to the amplifier by hiding it under floor mats or by running it under the plastic panels between the doors and the driver's side seats.
- Hide the cable under the boxes between the doors and the seats or simply slide it under the floor mats.
- Leave the blue wire next to the red electrical wire.
Method 3 of 3: Install the Subwoofer and Amplifier
Step 1. Connect the amplifier ground wire to the vehicle's chassis
Since this is a closed electrical system, you must ground the amplifier to the chassis of the vehicle. Find an unpainted metal surface on the vehicle and mount the grounding loop to the metal or tear a piece of cloth in an inconspicuous area to expose the metal underneath.
- If you ever notice something burned near the subwoofer when using your new audio system, you should check the ground wire.
- You cannot connect the cable to a painted surface. You can use sandpaper to remove paint from a small metal section if necessary.
Tip:
some vehicles come with a designated area where you are supposed to connect ground wires. You should consult the manual before tearing the fabric.
Step 2. Connect the line converter to the amplifier
Place the amplifier near the area where it is grounded to the chassis. Connect the blue wire from the line converter to the input port of the amplifier. If there are any RCA connectors that you are supposed to connect, run these cables down the same path that you hid the power cord.
In some audio systems, you only need to connect the blue wire. In other systems, you must also install RCA cables. Sometimes all 3 wires are bundled together
Step 3. Connect the power cord to the opposite side of the amplifier
Connect the red electrical wire from the battery to the amplifier. If the open end of the power cord is a loop and the opening for the cord is a groove, use wire cutters to strip the end of the cord to expose a 1 to 2 cm (½ to 1 inch) length of copper wire. Slide it into the opening and press down on the pin to close the connection.
If the power cord opening above the amp is a small round handle, try unscrewing the cap and wrapping the cord over the screw. Then, tighten the cap over the loop to snap it into place
Step 4. Connect the RCA cables from the subwoofer to the amplifier
Connect the left channel of the subwoofer to the left channel of the amplifier and the right channel of the subwoofer to the right channel of the amplifier. If there is a separate power cord for the subwoofer, you may need to connect it to the amplifier as well.
Step 5. Reconnect the battery and test the system
Before reassembling the instrument panel, reconnect the negative battery terminal. Turn the volume knob all the way down and then start the vehicle. Try to play music and turn up the volume slowly. If you do hear the music, go ahead and shut down the vehicle before reinstalling the instrument panel using the same clips and parts.
- If the main unit won't turn on, you need to check the wire connections in the harness.
- If the audio sounds distorted, you should check the line converter to make sure your connections are clean.
- If you don't hear anything, check the amp to see if it's getting battery power.