Troubleshooting Common Car Amplifier IssuesUpdated 4 hours ago

Sometimes, even with the right setup, car amplifiers don’t work as expected. At Big Jeff Audio, we see a few common issues customers run into during installation. Here’s a rundown of some typical problems and steps to help you troubleshoot and fix them, so you can get your audio system sounding great.

Factory Radios and Security Codes

If you’re using a factory radio, it may have a built-in anti-theft security code that needs to be reset to work with an external amplifier. Usually, you’ll find instructions for resetting it in your vehicle’s manual or by checking online. Dealership service departments can also provide codes if needed.

Testing Your Amplifier’s Power Supply with a Multimeter

Using a multimeter is essential for accurately diagnosing power issues in your amplifier. Check out our multimeter collection to find a quality tool. Here’s a basic outline to guide you through the testing process:

1. Check Voltage at the Amplifier: Use the multimeter to test for +12 volts DC between the amplifier’s power and ground terminals.

   • No voltage? Check the inline fuse near the battery to see if it’s blown. If the fuse is intact, a loose or disconnected wire could be the cause. Find the right audio wire for your setup in our audio wire section - not sure what wire you need? Check out our article here to help you pick the proper gauge wire!
   • Voltage present? Proceed to test the remote turn-on lead.

2. Testing the Remote Turn-On Lead: With the multimeter, measure between the amplifier’s ground and remote lead terminals. No voltage here usually indicates a disconnection in the remote lead.

No Sound from Speakers, Even Though the Amp Powers On

To track down the problem, start from the stereo and work towards the speakers:

• Double-Check Stereo and Amp Settings: Make sure the amp’s gain is turned up slightly and that filters are set as needed. Also, confirm your source is actively playing music, and that RCA cables are securely connected.
• Test RCA Cables and Stereo Output: Disconnect the RCA cables at the receiver, and touch the tip of each connector. If the speakers hum, the wiring is intact. If not, it may indicate a problem with the RCA cables or receiver output. If you find your RCA cables to be giving an issue, you can find replacement RCA cables here!

Speaker Wiring and Connections

Incorrect or loose wiring can lead to silent speakers. A quick test with a 9-volt battery helps identify whether the speaker wiring is working:

• Battery Test: Disconnect the speaker wires from the amplifier, and use a 9-volt battery to briefly touch each wire. A “click” sound means the speaker and wiring are functional.

Troubleshooting Noise: Humming or Buzzing

Most noise issues can be traced back to poor grounding. Check that the ground wire is securely connected to a clean, paint-free metal surface in your vehicle. Also, look for any loose wires that could be causing interference, even at the battery terminals.

Power Demands and Overloading

High-power car audio systems can sometimes draw more power than your vehicle’s electrical system can comfortably supply. This can lead to issues like dimming headlights when bass hits or even potential damage to your alternator or battery over time. Here are some ways to manage and improve your system’s power efficiency:

1. Capacitors for Extra Power: A capacitor, like our Audio Pipe 3.5 Farad Capacitor can be added to your amplifier’s power cable to provide short bursts of power during those heavy bass notes. Capacitors store energy and release it when your amplifier demands more power than the alternator can instantly supply, reducing strain on your car’s battery and preventing voltage drops.

2. Upgrade Your Alternator: For systems with high wattage, your factory alternator might not be able to keep up. Upgrading to a high-output alternator can help supply consistent power to your audio system, preventing overloads and extending the life of your electrical components. This upgrade is essential for serious audio setups, especially if your system is running over 1,000 watts RMS.

3. Replacing Your Car Battery: If your car’s battery isn’t holding a strong charge, it might struggle to meet your amplifier’s demands, especially when the system is under high load. A quality car battery designed for higher power outputs can help maintain stability and provide a reliable power source. 

   • We recommend the Big Jeff Audio 12V 22AH Lithium Battery. With a max power rating of 6000 watts, 293 Watt-hour capacity, and built-in cell balancing, this battery ensures your system has a steady, powerful energy supply. Designed for easy integration, it features copper terminals for optimal conductivity and supports up to 14.7 volts, making it a top choice for high-drain audio systems. By combining these upgrades, you can help ensure your car audio system performs at its best, even at high volume.