Car fuse help
The basics of checking, identifying and replacing car fuses.
How to check and replace a fuse
- Switch off the ignition and all electrical equipment. Take the key out, or move a keyless fob away from the car.
- Open the fuse box and find the fuse using the number on the cover legend or the chart on this page.
- Pull the fuse straight out with the plastic fuse puller (usually clipped inside the fuse box) or fine-nose pliers.
- Look at the metal strip inside the fuse. A broken or burnt strip means it has blown.
- Fit a new fuse with exactly the same amperage rating. The number on top and the colour should match.
- Refit the cover, switch on and test the component.
- Never fit a fuse with a higher amperage rating than specified. It can let wiring overheat.
- Never bridge a fuse with wire, foil or anything else.
Blade fuse colour codes
Standard mini and ATO blade fuses are colour-coded by rating. Always go by the number printed on the fuse.
| Rating | Colour |
|---|---|
| 2A | Grey |
| 3A | Violet |
| 4A | Pink |
| 5A | Tan |
| 7.5A | Brown |
| 10A | Red |
| 15A | Blue |
| 20A | Yellow |
| 25A | Clear / natural |
| 30A | Green |
Fuse keeps blowing?
A fuse that blows again straight away is doing its job. Something on that circuit is drawing too much current. Common causes are damaged wiring shorting to the bodywork, a failing motor or socket, water getting in, or a faulty accessory. Fitting fuse after fuse, or a bigger fuse, won’t fix the fault and can overheat the wiring. Have the circuit tested by an auto electrician.
Fuse or relay?
A fuse protects a circuit by breaking when too much current flows. A relay is an electrically operated switch that lets a small control circuit turn on a high-current one, such as a starter or fuel pump. Fuses fail visibly. Relays usually fail without any outward sign.