In most vehicles that use standard ATC/ATO blade fuses, a 15-amp fuse is blue.
Color coding for automotive fuses helps technicians and drivers identify the amperage at a glance. While blue is the conventional color for 15A in blade fuses, variations can occur between brands and between fuse formats such as mini fuses or glass fuses. Always verify using the fuse body label or the vehicle’s manual.
Color codes explained
Color coding is a quick-reference system used on common blade fuses. The color associated with the 15-amp rating is typically blue, though shades may vary slightly by manufacturer. When in doubt, read the markings on the fuse itself or consult the owner’s manual for the exact specification.
- 15A — Blue
This blue cue is the most reliable indicator for a 15-amp blade fuse in standard automotive fuse kits, but always confirm with labeling to avoid misreading.
Note on other fuse formats
Other formats—such as micro fuses, mini fuses, or glass tube fuses—may use different color schemes or markings. Manufacturers may differ in their color palettes, so it’s important to rely on the labeling on the fuse body and the vehicle’s documentation when identifying ratings.
Replacing a fuse: step-by-step guide
When replacing a blown fuse, following a careful process helps ensure electrical safety and correct operation of the protected circuit.
- Turn off the vehicle and locate the appropriate fuse box using the owner’s manual or fuse diagram.
- Locate the blown fuse by inspection or by using the vehicle’s fuse diagram; remove it with a fuse puller or insulated pliers.
- Check the rating on the fuse to confirm it is the same amperage as the one you’re replacing (for a 15A fuse, you should use a 15A replacement).
- Insert the replacement fuse firmly into the same socket, ensuring it sits flush and fully seated.
- Turn on the ignition and test the circuit that was protected; if the fuse blows again, there may be a short or another electrical fault requiring professional diagnosis.
Using a fuse with a higher rating than specified can pose a fire risk, while a lower rating may cause nuisance blowing. If replacements repeatedly fail, seek expert assistance to diagnose underlying wiring issues.
Summary
For most cars employing standard blade fuses, a 15-amp fuse is blue. Always verify the rating on the fuse body and consult the vehicle manual when replacing fuses. If a fuse continues to fail, a deeper electrical diagnosis may be necessary to identify a fault beyond a simple fuse replacement.