Automotive fuse color codes
Automotive blade fuses are color-coded by amperage so you can identify a fuse rating with a glance — even without reading the number printed on the body. The color standard applies to ATC/ATO (standard blade), ATM/APM (mini blade), and ACS (micro blade) fuses. Maxi blade fuses share most colors but cover higher amperages.
Standard blade fuse color codes (ATC / ATO / APR)
These are the most common fuse type found in automotive fuse boxes. ATC and ATO are the same electrical rating; ATC has a closed body, ATO has an open body.
| Color | Amperage | Common designations | Notes |
|---|---|---|---|
| Black | 1 A | ATC1, ATO1, F1A | Low-current control circuits |
| Gray | 2 A | ATC2, ATO2, F2A | Low-current circuits |
| Violet / Purple | 3 A | ATC3, ATO3, F3A | Alarm, accessory circuits |
| Pink | 4 A | ATC4, ATO4, F4A | Sensor, control circuits |
| Tan / Beige | 5 A | ATC5, ATO5, F5A | Very common — accessories, gauges |
| Brown | 7.5 A | ATC7.5, ATO7.5, F7.5A | Cigarette lighter, accessories |
| Red | 10 A | ATC10, ATO10, F10A | Very common — lights, radio, power windows |
| Blue | 15 A | ATC15, ATO15, F15A | Very common — AC blower, wipers, trailer lighting |
| Yellow | 20 A | ATC20, ATO20, F20A | Power windows, seat heaters, headlights |
| Natural / Clear / White | 25 A | ATC25, ATO25, F25A | Power seats, audio amplifiers |
| Green | 30 A | ATC30, ATO30, F30A | ABS, fuel pump, cooling fan |
| Teal / Aqua | 35 A | ATC35, ATO35, F35A | High-current accessories |
| Orange | 40 A | ATC40, ATO40, F40A | High-current circuits — use MAXI blade instead where available |
Mini blade fuse color codes (ATM / APM)
Mini blade fuses are physically smaller than standard ATC fuses but use the same color code. They are not interchangeable with standard blade fuses despite similar colors — the body width is different.
| Color | Amperage | Notes |
|---|---|---|
| Tan | 5 A | ATM5 |
| Brown | 7.5 A | ATM7.5 |
| Red | 10 A | ATM10 |
| Blue | 15 A | ATM15 |
| Yellow | 20 A | ATM20 |
| Clear / White | 25 A | ATM25 |
| Green | 30 A | ATM30 |
Maxi blade fuse color codes (MAXI)
Maxi blade fuses are larger than standard ATC fuses and are used for high-current circuits, typically in an underhood fuse box. The color codes are the same for overlapping amperages but extend to higher ratings.
| Color | Amperage | Notes |
|---|---|---|
| Yellow | 20 A | MAXI20 |
| Clear / White | 25 A | MAXI25 |
| Green | 30 A | MAXI30 |
| Orange | 40 A | MAXI40 — alternator output, main battery feed |
| Red | 50 A | MAXI50 |
| Blue | 60 A | MAXI60 |
| Tan | 70 A | MAXI70 |
| Black | 80 A | MAXI80 — main fuse, high-current battery circuits |
Quick tip
Reading the number on the fuse
The amperage is printed directly on the fuse body and/or embossed on the metal terminals. When replacing, always read the number rather than relying solely on color — aftermarket fuses occasionally use slightly different shades.
Quick tip
Identifying a blown fuse
Hold the fuse up to a light. The thin metal bridge inside a working fuse is intact. In a blown fuse it will be broken or melted, and the plastic body may show slight discoloration. Use a test light or multimeter for fuses you cannot see through (ceramic types).