Improving your car's sound system can make driving much more enjoyable. While some opt to purchase expensive new speakers or head units, simply rewiring your existing car stereo can provide a significant audio upgrade. With some basic tools and a little time, you can boost the power going to your speakers for louder, clearer sound. Follow this guide to learn how to easily rewire your car stereo on your own.
Assess Your Car Stereo Setup
Before getting started, take some time to assess your car's current stereo system. This will help you understand what needs to be improved.
Identify the Head Unit
The head unit is the main stereo control center. It will likely have buttons for radio tuning, CD or auxiliary playback, volume control, etc. Making note of your head unit model can help you find a rewiring solution specific to your car.
Check the Speakers
Look to see what size speakers are installed in your car. Standard sizes are 4, 5, or 6.5 inches. Larger speakers can handle more power and produce better sound quality. Writing down the speaker sizes will assist in finding suitable replacement wires.
Look for External Amplifiers
Some systems have external amps to boost speaker power. If present, making note of the amp model and output will be helpful for rewiring.
Consider Sound Goals
Think about the audio improvements you're hoping to achieve. Do you want louder overall volume, better clarity at high volumes, improved bass response? Defining these goals will inform the rewiring approach.
Gather the Right Supplies
With your system assessed, it's time to get the necessary supplies for rewiring your car stereo. Having these materials on hand will make the process smooth and efficient.
New Speaker Wire
Higher gauge wire, such as 12 or 16 AWG, can better handle increased power delivery. Ensure you get enough wire to connect all speakers from the head unit wiring harness.
Wire Strippers
A proper wire stripping tool will cleanly remove just the right amount of insulation from the wire. This helps create solid connections.
Electrical Tape
High quality electrical tape seals connections and prevents shorts. Avoid cheap vinyl tape which can melt or tear over time.
Crimp Connectors
Crimp connectors securely attach wires using only hand pressure. Choose heat shrink tubing connectors to maximize connection integrity.
Multimeter
A multimeter lets you verify wire continuity and test for shorts during the rewiring process. This can prevent serious electrical issues.
Wire Loom and Grommets
Protect new speaker wires from rubbing and vibration using flexible wire loom. Grommets properly pass wires through metal barriers while avoiding damage.
Disconnect the Battery
Before going hands-on with any car stereo wiring, always disconnect the negative terminal of the battery first. This cuts all power to avoid shocks, sparks, and accidental electrical shorts.
Access the Existing Wiring
To swap out the factory speaker wires, you first need to locate the wiring harness. This is usually accessible behind the head unit.
Remove the Head Unit
Refer to your vehicle-specific guide to properly extract the head unit. You will likely need to remove the trim first, followed by several mounting screws.
Unplug Wiring Harness
Once the head unit is out, locate the wiring plug or harness at the rear. This provides power and ground and connects to speakers. Unplug this from the head unit.
Review Wire Colors
Note the colors of the existing speaker wires coming from the wiring harness. This varies by car brand and stereo type. Common arrangements are:
- Front left +: White
- Front left -: White/Black
- Front right +: Gray
- Front right -: Gray/Black
- Rear left +: Green
- Rear left -: Green/Black
- Rear right +: Purple
- Rear right -: Purple/Black
Run New Speaker Wires
With access to the car's wiring harness, you can now upgrade the existing speaker wires with thicker, higher quality replacements.
Match Wire Gauge to Speakers
Use a wire gauge capable of handling your amplifier's power output. For most cars, 16 AWG wire pairs work well. Larger aftermarket speakers may benefit from 12 AWG wire.
Determine Needed Length
Measure from the wiring harness to each speaker location. Add some extra length to work with. You want just enough wire without creating messy loops.
Connect Wires Securely
Carefully twist matching colors together, solder if possible, and seal with adhesive lined heat shrink connectors. This prevents loose connections that can cut sound.
Avoid Interference
Keep left and right channel wires separated. Crossing these can induce noise and degrade stereo imaging. Use wire looms and grommets to protect wires.
Double Check Wiring
Before buttoning everything up, verify proper continuity of all connections using a multimeter. Recheck wires if issues are found.
Upgrade Ground Wires
In addition to speaker wires, also upgrading the ground wires from the stereo can improve sound clarity.
Run Thicker Ground to Chassis
Add an auxiliary ground by running thick 8 or 10 AWG wire from the head unit ground to a bare metal spot on the car chassis.
Ground Amplifiers Separately
If amplifiers are installed, ground them to the chassis at a different location than the head unit using similar heavy gauge wire.
Ensure Tight Connections
Remove paint between grounding locations for optimal metal-to-metal contact. Secure wires using screwdrivers to avoid loosening.
Test and Tune the System
With new wiring installed, it's time to fire up your car stereo and hear the improvements.
Reconnect the Battery
Safely reconnect the negative battery cable now that rewiring is complete. This will restore power to the stereo system.
Check for Noise
Turn the stereo on to verify it powers up normally. Listen closely for any whining or odd noises which could indicate issues.
Test Audio Quality
Play familiar tracks while paying close attention to sound clarity, stereo imaging, bass response. The new wiring should provide obvious improvements.
Set Gain on Amplifiers
If external amps are installed, set their gain controls properly so maximum clean sound can be achieved without distortion.
Enjoy the Upgrades!
Bask in the musical bliss coming through your newly rewired car speakers. Drive safe while rocking out!
Rewiring your car stereo speakers and ground wires can seem intimidating, but armed with the right information it can be accomplished easily. The improvements to overall sound quality are well worth the effort. Just take it slow, use care when working with electrical systems, and soon you'll be enjoying audiophile-quality tunes from your existing system.