A combination of fuses, circuit breakers, and fusible links protect the electrical circuits of the vehicle, the main fuse/relay panel of which is located in the engine compartment and the interior fuse/relay panel of which is located in the passenger compartment (2009 and earlier models have it below the passenger side of the instrument panel and 2010 and later models have it underneath the driver side). There are small, medium, and large fuses used in the fuse blocks with the same blade terminal design; the medium and large fuses may be removed by hand, but the small fuses must be removed with a plier or fuse-puller tool made of plastic. Whenever there is any electrical component failure, it is the first step to check the fuse and the most effective way of doing so is to check the presence of power on the exposed terminal tips of each fuse using a test light, where one side has power and the other side has no power then the fuse is blown and this can also be detected visually. It is also important to ensure that the blown fuses are replaced with the correct type because the different rating fuses might fit physically but still different as this will be the correct one to protect the respective electrical circuits, and the value in the amperage should be carved into the top of the fuse body. When a replacement fuse fails instantly, it must not be replaced until the fault is located and corrected as it is normally a short circuit due to a damaged wire. Also, there are circuits that have fusible links that provide protection against overcurrent, and which are found in a circuit that is not normally fused, or where the current can be very high, as in the connection between the alternator and the battery; the fusible link is designed to melt away should excessive current be applied to it, and then troubleshooting becomes necessary before installing another circuit.