Free Shipping on all orders over $100

New collections added! Learn more

Down4Sound Amps are now Available

What is a "Big 3 Kit"? And should I do it?

What is a "Big 3 Kit"? And should I do it?

Jace Finnell |

If you’re new to car audio, you might not have heard of a Big 3 Kit, but it’s a simple and effective upgrade for your car’s electrical system—especially if you’re running powerful audio equipment. A Big 3 Kit upgrades three important wires in your car with thicker ones. These wires help power flow more easily through your vehicle, which prevents your electrical system from struggling when you have a strong stereo setup.
Here’s what the Big 3 Kit does:
  • Battery Negative to Chassis Ground: This replaces the wire that connects the battery to the car’s frame (or chassis) with a thicker one to improve grounding.
  • Alternator Positive to Battery Positive: This upgrades the wire that carries power from the alternator (which generates electricity) to your battery, making it better at handling extra power.
  • Chassis Ground to Engine Block: This strengthens the connection between the engine and the car’s frame for smoother energy flow.
By installing a Big 3 Kit, your car’s electrical system gets a boost, making it easier to handle the extra demand from big amplifiers and subwoofers. This helps keep your battery and alternator from working too hard, giving you a more reliable and powerful sound system.
If you’ve noticed your headlights dimming when your music hits hard, it’s actually a sign that your car’s electrical system is struggling to keep up with the power demands of your audio setup. Installing a Big 3 Kit is an easy and affordable fix for this issue. The Big 3 Kit strengthens key connections in your car’s electrical system by swapping out thin factory wires for thicker ones, which helps power move more smoothly and efficiently. By doing this, it stops those big power dips that cause your headlights to dim when your subwoofers hit hard bass notes. Not only is this upgrade simple, but it’s also cost-effective, especially compared to other options like upgrading your alternator or battery. A Big 3 Kit is a quick way to give your electrical system the extra boost it needs to support your powerful audio gear—keeping your headlights bright and your system sounding great!   If you're serious about taking your car audio system to the next level, it’s not just about having powerful subs and amps—you also need to make sure your vehicle's electrical system can keep up. Installing a Big 3 Kit is a great first step,