Cars rely on complicated electronics. If there's a problem that shorts something out, a small car fuse under the dash board will blow out. That can cause major functions of your car to stop working, or even shut it down all together. Having a few spare car fuses on hand will get everything working again in no time. You can easily find a few cheap car fuses, but make sure you get a quality set. Replacing a car fuse may only be a temporary fix. If you find a fuse is blowing out too often, there could be a wiring problem with your car.