Troubleshooting automotive electrical components, such as the wiring and fuses, can be done with little effort with a test light. Test lights and fuse testers are available at any hardware or auto parts store. Car radios have several different wires, such as the hot wire, the ground wire, wires for each speaker and a wire for the antenna connection. A test light will light up when you have a constant flow of current to the wire. One end of the test light has a clamp on it. This clamp should be attached to a good ground source.
Determine whether or not the radio has been modified. Sometimes when an aftermarket deck is installed, a power wire is run from another source, such as the car battery. Make sure there are no loose wires on the battery cable ends.
Remove the cover from the fuse block. Your vehicle owner's manual will indicate the location of the radio fuse. Use a test light to check the fuse. If it is bad, replace it.
Pull the radio out from the dashboard and check the fusible links. These links have a factory-installed wire attached at each end. If you find a blown fuse, replace it.
Check the ground wire on the radio and the antenna wire for a solid connection. If none of these tests solves the problem, the fault may be in the radio itself.
