Wire Gauge Chart for Car Audio Systems - dummies Car Audio For Dummies. To avoid problems and get the best sound, determine the fuse ratings of your amplifiers and their distance from the battery and refer to the following chart to determine the proper power-wire gauge. For example, if your amplifier is drawing 60 amperes of current and the distance to the car’s battery from.. Gauge wire used for stock radio? | Tacoma World Oct 27, 2011The Metra harness plugs into the factory plugs and has bare wires on the other end. The Pioneer has a harness that plugs into the back of the radio and has bare wires on the other end. It's those bare wires that need to be matched up and I will solder/heatshrink them.