A blown fuse is one of the more common roadside problems. The result of a blown fuse can be major (the car stops running) or minor (the radio stops working). Here’s how to check for a bad fuse and how to replace it if necessary.
CHECKING FOR A BLOWN FUSE
1. LOCATE THE FUSE BOX AND REMOVE COVER.
The location of the fuse box varies greatly, but they can usually be found in the engine compartment or in the dashboard. Depending on your vehicle, you may have more than one fuse box. Check your owner’s manual for the
location of all fuse boxes and remove any protective covers
2. TEST THE FUSES.
Place the metal contact or tips of your tester to the exposed metal parts of the fuse. If you make good contact, your tester will light up. If it doesn’t, check it a couple of times and check another fuse to make sure you are making good contact. If your tester doesn’t light up, you have a bad fuse
If you are using a meter, turn the meter setting to “continuity” or “resistance,” usually marked with an omega symbol. If the fuse is good, the meter will show almost no resistance or zero resistance, and if the fuse is bad, it will not make a connection in your meter
Check all of the fuses for continuity, and note any that are bad.
CHANGING A FUSE
1. PULL THE FUSE.
Using either your fuse puller (ours was built into the tester) or a pair of pliers, gently pull the fuse from its pocket
2. INSPECT THE FUSE.
If the fuse is blown, the metal in between the two power posts will be melted and will not be connected. You may be able to see a broken or burned spot in the metal
3. INSTALL THE NEW FUSE.
Using a fuse of the same size and color (the color is specific to how much power the fuse can protect), press the new fuse into the socket. If the fuse is in a difficult place, you can use your fuse tool or pliers to gently install it. Push it all the way in to make good contact
4. CHECK THE NEW FUSE.
Re-check the new fuse to make sure it is good, and then try the electronics that were failing to see if that solved the problem. If you continue to blow circuits, you need to have a professional look at your car.
You need a continuity tester that will test a circuit with the power off. You can use an expensive multimeter or a simple circuit tester that may be included in your box of fuses. Either will do the job just fine. Your checker does need to be self-powered.