How to Test the Fuses on Your Car

Dec 08, 2023

It's a quick and easy job and could save you a trip to the mechanic.

Has an electrical component randomly stopped working on your vehicle? Have you replaced the part, and it acts as if nothing was done? Chances are, you may have blown an electrical fuse on your vehicle. These are put in place to protect the electrical system on your vehicle from overloading its circuits.

Fuses are an important part of any electrical system, as they prevent potential failures from happening. Like most electrical systems, fuses also exist in your automobiles for the same reason. Anyone can test fuses, and here's how you do it.

Testing a blade fuse is an incredibly simple process that can be done with minimal disassembly. In this particular vehicle, the fuse box is located on the driver's side of the dash between the door. Different manufacturers place fuse boxes in various locations, so be sure to utilize your owner's manual to locate it if necessary.

Upon pulling the fuse panel cover, you will be presented with a plethora of blade fuses parallel to each other. Commonly, the functions of these fuses are presented on the fuse panel cover that you just removed. If nothing is present, your owner's manual can provide that information for you. If you don't have your owner's manual, there are heaps of ways to find manuals online for free.

Blade fuses have numbers on the outer casing, representing their amperage ratings. Fuses, or electrical breaks, are put in place to prevent electrical fires and overloaded circuits. The amperage rating is the amount of current the fuse can withstand before it breaks, ranging from half an amp to 120 amps.

Blade fuses come in multiple sizes—Micro2 and Micro3 being the most common on automobiles. Blade fuses are not interchangeable by size and should only be replaced with parts matching their original specifications.

Testing a blade fuse is nothing more than checking its continuity. Since fuses are designed to break when there is a malfunction in the circuit, a functional fuse should have full continuity. Fuses are commonly in clear or transparent casings, making malfunctioning ones easier to identify and vice versa. A visual test is one of the simplest ways to test your fuses, though it can be time-consuming since each fuse will have to be pulled.

Automotive retailers sell dedicated fuse testers that allow you to test your fuses, though it isn't really necessary. While it is perfectly okay to utilize such tools, you can save some money if you already own a multimeter! Multimeters are complex electronic tools that truly expedite electrical nightmares. Among the features a multimeter offers, continuity testing is one of them.

Depending on the fuse's construction, you may see small pins on the outer casing of it. Connect the two to complete the circuit using those pins and the two ends of your multimeter. A functional fuse will cause the multimeter to produce a constant sound, indicating that your fuse is working as it should. If there isn't a noise coming from one of your fuses during your test, this indicates a break in the fuse, and it must be replaced with an appropriately matching candidate.

Even if you aren't mechanically inclined, there is no need to fret, as testing your fuses is as easy as diagnosing a vehicle gets. Whether you test visually by looking at the outer casing or with the aid of electronic tools, the process remains simple for any user. In addition, fuses are relatively cheap and usually come in multiples, so you will always have a spare. This can save you time and money by saving a trip to the mechanic.

Based on the East Coast, Joshua Ko has been an automotive writer for MakeUseOf for over a year and is a die-hard European car enthusiast. He primarily covers car tips and tricks and DIYs. After graduating from the Pennsylvania State University, he spends most of his time outdoors, writing, or in the garage.