You should be able to easily spot if the fuse has blown or not. On the blade type or the older clear glass tube fuses, just look in, and if the inner contact is burnt in half, or there is obvious black burn marks, then the fuse is bad.

If your still not sure, another way to check is to put a meter across the two sides of the fuse, and you should get little to no resistance. At this point I would just put in a new fuse and see what happens.       Note: Only do this if this is the first time the fuse has blown. If this is a reoccurring problem, then proceed to the next step below.

                      blown blade fuse            blown tube fuse

If every time you put a fuse in, it blows, or if it blows quite frequently, then you have a more serious problem in the wiring or the component after the fuse. A fuse is designed to protect the component or part it is wired to against overloads, and power spikes. Most likely if a fuse continues to blow, then it is not a power spike, it is a component drawing to many amps, or the wiring /part is shorted.

To narrow this down, first unhook the suspected part from it's wiring. Now is when to pull out any diagrams or wire charts you may have for the part. You need to find the power wire(s) and separate it to the side for now. Keep in mind for some parts there may be more than one power wire. Now with the fuse and part out, check for resistance between the power wire(s) and the other included wires. Generally the power wire should not be electronically connected to any other wires, but double check your wire diagram to be sure.

If you find a power wire shorted to another wire or ground, and the wire diagram shows it not connected to that other wire, then you have found the problem. Fix the wire, plug your fuse and part back in, and try it again. It should now work. If it still does not work, or you originally found no wire problems, then the part could be drawing an excessive load. The best thing to do here is take that part to a certified dealer or if economically possible, just buy a new part. If after all this, you still have a blowing fuse, then I would suggest a complete rewire either yourself or a certified electrician.

Hope this helps find a pesky fuse fuss, and as always, have fun and be safe.   

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