Grounding protects your car audio components from electrical overload and prevents alternator whine from creeping into your music.

Bad grounds can make your amp cut out, and create excessive heat, which can lead to vehicular fires.

An ounce of prevention is worth a pound of cure. 

This is especially true when working with car stereo systems.

Turning your system up creates a demand from the amplifier for more current. Without a good ground, your system cannot create this current, which creates clipping issues with the amplifier.

Properly grounded systems help stabilize voltage levels.

The ground wire is crucial- It can save or destroy your system, so it’s important to get this step right.

You’ll want to set your ground wire as close to your amplifier as possible, using the same gauge ground wire as power wire. 

Ideally, this should be less than 12 inches away from your amp. 

1.) Find a bolt that is secured to your vehicle’s frame. 

If you cannot find one, you will need to create a grounding point by drilling into your chassis. 

Should you need to drill your grounding point, select an area with uncovered metal and drill a hole for your bolt or screw. Be mindful of fuel tanks, wires and anything else in the path of your drill.

If you cannot find a bare metal surface within 1.5 feet from your amplifier, you will need to prepare a surface by grinding any paint, dust, or rust down to the bare metal. 

2.) Clean this area thoroughly- Bare metal is essential for this ground connection. Exercise caution to avoid drilling into your gas tank, existing wiring, and gas/brake lines. 

Make sure that your bolt is free of any rust, dust, or paint and is connected directly to the metal chassis of the vehicle. If there is paint or residue present, sand it or grind it down to the bare metal. 

Now we’re ready to connect the ground wire.

Having created and prepared the grounding point, the next step is to connect the ground wire terminal to the grounding bolt. 

3.) Tighten the ground wire onto the terminal, using a washer and nut. Make sure it is secure so it will not come loose over time from vibrations. Using a star washer will make sure your washer bites into the metal to keep your ground terminal in place.

To make sure you’ve correctly grounded your wire, let’s test it.

1.) Using a digital multimeter and a lead extension, touch one lead to the ground location and the other lead to the negative battery post. 

2.) Touch the DMM leads together to determine what the resistance of the leads and extensions are. Subtract the resistance of the DMM and leads from the resistance you measured in the previous step!

You should be getting a reading at or around .5 Ohm.

3.) If the DMM is reading greater than 0.5 Ohm, check your connections, one by one, until it does.

You’ve successfully grounded your amplifier!

Use this guide for Installing Your First Car Amplifier.