The first step when working with equipment that may be controlled by a fuse is to check all of the fuses with a test light. First, turn the key to the "on" position. Probe the back side of each fuse. There are two places to check. If the test light doesn't illuminate on either side of the fuse, that fuse is most likely blown. If the test light only illuminates on one side, you'll need to look in the owner's manual to see what that circuit feeds. Certain circuits require that you activate something to illuminate the test light-for example, turning on the headlamp switch to energize that particular fuse.