Your vehicle's electrical ground is what allows electricity to flow back to the battery, completing the circuit. For car audio enthusiasts, the factory grounding may be insufficient to accommodate the additional devices installed on the vehicle. If the car's lights dim when you turn up the radio, it maybe time to improve the ground connections to the vehicle's frame. This job should be your first step in improving the electrical system and is inexpensive.
Disconnect the negative black terminal on the vehicle's battery. This is done by loosening the bolt and pulling the terminal upward with your hand. Set the ground wire in a position away from the positive terminal on the battery.
Follow the battery's ground wire to its connection with the chassis. Loosen the bolt that fastens it to the frame and set the ground wire aside. Sand the connection's location with sandpaper to remove the paint and rust.
Measure the length of the stock ground wire and cut a new section of 1/0-gauge wire to match that length.
Strip three-fourths of an inch of insulation off both ends of the wire with a utility knife. Insert one end of the wire in the new battery terminal and tighten the terminal with an Allen key. Insert the other end of the wire in a ring terminal and compress the terminal with pliers to fasten it.
Align the ring terminal with the chassis ground bolt hole and secure it with the removed bolt. Tighten with a wrench. Do not attach to the negative terminal on the battery yet.
Locate the vehicle's alternator. This is the coffee-can-sized electric motor fastened to the outside of the engine. Remove the bolt fastening the ground wire to the alternator. Follow the ground wire to the chassis and remove from the chassis. Sand the chassis’s ground location to remove the rust or paint.
Measure and cut a new section of wire equal in length to the alternator's ground wire. Strip three-fourths of an inch of insulation off both ends of the wire with a utility knife. Insert both ends of the wire into ring terminals and compress the terminals with pliers to fasten them.
Align one ring terminal with the alternator's ground connection and fasten with the removed bolt. Fasten the other end of the ground wire to the chassis’s ground connection and tighten the bolt with a wrench.
Remove the alternator's positive wire connection and pull the wire out of the engine bay until it reaches the battery. Loosen the positive terminal on the battery and pull off the terminal. Cut the wires as close as possible to the terminal.
Measure and cut another section of 1/0 wire that matches the length of the factory's battery to alternator positive connection. Strip three-fourths of an inch of insulation off both ends of the wire. Install a ring terminal on one end and a battery terminal on the other end.
Fasten the wire to the positive terminal on the alternator and the positive terminal on the battery. Strip three-fourths of an inch of insulation off the other wire(s) that were connected to the battery’s positive terminal. Push these wires into the other terminals on the positive battery terminal and secure by tightening with an Allen key.
Connect the negative ground wire to the batteries terminal and tighten with a wrench. Secure the loose wires with cable ties.
