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Automotive Reference

Automotive Fuse Types & Amp Colors

Every blade fuse tells you its rating by colour — and comes in five physical sizes. Here's the colour-to-amp code and how to tell a mini from a maxi.

The five blade sizes

Same idea, different footprint. Match the physical size to the empty slot, then the colour (amperage) to the circuit. A too-big fuse is dangerous — it won't blow when it should.

Micro2smallest LP-Minilow profile Mini (APM)very common Standard (ATO)the classic Maxi (APX)high current

Colours above are illustrative — a fuse's real colour tells you its amperage, per the chart below.

Colour = amperage

This colour code is standard across mini, standard and (mostly) maxi blade fuses.

ColourRating
Black1 A
Grey2 A
Violet3 A
Pink4 A
Tan5 A
Brown7.5 A
ColourRating
Red10 A
Blue15 A
Yellow20 A
Clear25 A
Green30 A
Orange40 A

Maxi fuses cover the higher end (30–120 A) and a few colours differ at the top; always confirm the number printed on the fuse itself.

Never fit a higher-amp fuse to stop one blowing. The fuse protects the wiring — a bigger fuse lets the wire overheat and can start a fire. If a fuse keeps blowing, fix the fault, don't upsize it. Replace only with the same rating.

Common questions

What colour is a 15 amp fuse?

Blue. The common ones to memorise: red = 10A, blue = 15A, yellow = 20A, green = 30A. The full code runs from black (1A) up to orange (40A).

Can I use a mini fuse instead of a standard one?

No — they physically don't fit the same slot. Match the size (micro, mini, standard/ATO, maxi) to the fuse box, then match the colour/amperage to the circuit.

Is it OK to put a higher-amp fuse in?

No, and it's a fire risk. The fuse is sized to protect the wire, not the device. A higher rating lets too much current flow before it blows, overheating the wiring. Always replace like-for-like.

How do I know if a fuse is blown?

Look through the clear top — a blown fuse has a broken metal strip inside. Or test across the two exposed tabs with a multimeter or a test light; no continuity means it's blown.