How to Bench Test a Car Stereo Before installing a car stereo, it is recommended that you bench-test it, especially if it is a secondhand one. Attempting to troubleshoot it after it has been fitted in the confined quarter of the vehicle’s dash will save you time and frustration. Bench-testing a car stereo is a basic operation because speaker wiring is linked into colors that are universally recognized throughout the industry. With just a few test leads, a replacement speaker, and a power source, you can swiftly bench-test a car audio in minutes. Make four 2-foot jumper cables from the roll of electrical wire that was previously cut. Using the electrical pliers, remove a half-inch of insulation from the ends of each wire and discard it. Place the stereo on a flat surface so that the display is facing you. The four speaker cables are as follows: two white, left-front; two grey, right-front; two green, left-rear; two violet, right-rear; two white, left-rear; two white, right-rear. Positive wires are those with solid colors, whereas negative wires are those with stripes. Using an alligator clip, attach the end of one jumper wire to the positive wire of the test speaker to complete the circuit. Connect the opposite end of the jumper to the positive wire of the grey pair on the other side of the circuit. Then repeat the process with the second jumper wire to connect to the negative speaker wire. The antenna lead should be inserted into the antenna socket on the stereo. Using an alligator clip, attach one end of a third wire to the positive terminal of the battery on its way out. Connect the other end of the wire to the red, yellow, and orange cables that come from the stereo system. Connect the fourth jumper wire to the back grounding wire of the stereo, and the other end to the negative terminal of the battery to complete the circuit. Activate the stereo system. Check to see if the display has electricity. Adjust the volume control, as well as the left-right and front-rear fade controls, while keeping an ear out for the volume to fade in and out at the appropriate times. Turn off the stereo and move the jumper wires to the next pair of wires in the chain For each pair of colored wires, repeat the process.