Car Audio Wire Running Guide

Too many people have burned their car to the ground by installing wire incorrectly, specifically, car audio wire. The most common cause of failure is incorrectly crimping lugs onto wires and properly running fuses. Sometimes wires slip out of lugs and short on the vehicle frame or chassis, and the improper installation of a fuse causes the wire to catch on fire and burn the vehicle to the ground.

The tools needed to properly run a car audio wire are; a hydraulic crimper (a punch and hammer work alternatively if a hydraulic crimper is not accessible), wrench set, drill (and drill bits), large gauge wire cutters, wire lugs, a fuse block, a fuse, electrical tape, rubber grommets, heat shrink tubing, and a heat gun or torch.

The first step in installing car audio wire is to set the run of wire at a proper length. Run the wire through an existing hole in the firewall or drill a hole in the firewall for the wire and place a grommet on the wire to seal it on the metal to prevent it from getting cut. If the wire used is 1/0 or bigger, run the wire under the vehicle instead.

Route the wire around the engine bay so it is away from any moving or hot parts. Cut the wire so there is still a little bit of wiggle room as if it were connected to the battery terminals.

When running wire under the vehicle, be careful of any rotating or hot items under the car. Zip tie the wire, so it is not the lowest point of the car. The wire should not be visible when looking at the car from a side angle, nor should it droop and get close to the ground. If the wire is being run in the vehicle through the firewall, route the wire through trim panels located on each side of the car. Most vehicles have stock wire routing locations that can be tapped into and used for safe routing

After the wire has been routed to its locations, the rear battery/amplifier and the front battery, cut the wire so there is roughly an extra two feet on both ends from what is originally anticipated. The extra length will be cut down to size after the final location is determined.

Crimping the wire is the second most important step in wire routing. Most car audio wire is oversized in comparison to welding wire, which most stores carry electrical lugs for. Pick electrical lugs that are one size bigger than the wire size in use. (Ex. 1/0 car audio cable is 2/0 welding cable.)

Using a large gauge wire cutter, lightly cut 3/8 to half an inch of sheathing off the wire (or to the depth of the electrical lug.) Be careful not to cut any strands of wire as each strand is responsible for carrying current. Slot the wire into the lug. Depending on the position the lug is being crimped on, a single layer of electrical tape can hold it in place.

For using a hydraulic crimper, the crimp can be done in the engine bay or trunk due to the small form and simplicity of the hydraulic crimper. Place the lug into the properly sized crimp and compress the lug until the crimper is maxed out. Simply turn the release valve on the crimper, and the crimp is complete. If using a hydraulic crimper is not an option, use a punch. If it is not possible to place a hard, flat surface where the crimp is, the wire must be pulled partially out of the car. Use a hammer to punch the center of the lug into the wire. The lug should fold in on itself and make a solid connection.

To finish the connector, use electrical tape and make at least two layers of tape around the round part of the lug and half an inch back on the wire. Slot the heat shrink over the lug and as close as possible to the flat part. Use a heat gun or torch to shrink the tubing.

Fusing is the next most important step. There must ALWAYS be a fuse between a source of power and input. A fuse should not be more than twelve inches away from the power source.

Cut the wire as close to the battery as possible. Crimp each end of the cut as shown in previous steps. For four-gauge wire and up, use an ANL style fuse holder. For anything smaller, a MAXI fuse system works too. There are two styles of ANL fuse holders. One has bolts on each end for lugs (a stronger method), and the other version has terminal inserts (a faster install method not requiring lugs but not as secure.

Connect the wire lugs to the proper sized fuse (fuse charts are available online). Mount the fuse block in a safe location far from any metal or moving parts. Place the cover over the fuse block and make sure it is secure.

After the fuse connection is jumped, the wire is successfully run.

There is no reason to skimp out on electrical equipment. There can be hundreds of amps flowing through a car audio power wire at any time. So much power can cause very big problems if it is not respected. Too many amateur installers and young people install wires wrong and burn down their cars. Taking just a little extra time and care can make the difference between a major insurance claim or some bump in the trunk.