Fuses protect a car's electrical circuits against overload. If an electrically-powered item stops working, it could be because the fuse has blown. If you replace a fuse and it blows again, there's almost certainly a fault in the wiring or in the item concerned.
You'll need some spare fuses of the correct type and rating - check the vehicle handbook or your Haynes Service and Repair Manual for details. This will also tell you which fuse protects which circuit, and where the fuse boxes are.
The fuse box is usually under a cover near the glovebox or instrument panel. Sometimes there's one under the bonnet as well (see above). Switch off the ignition before starting work.
2 To remove a fuse, simply pull it from the panel. On some cars there's a plastic tool for doing this - otherwise, use your fingers or some slim pliers.
3 A blown fuse is easily recognised by the melted wire between the two contact blades (left) - compare this with a good fuse (right). The replacement fuse must be of the correct rating - this is shown by its colour or by the number stamped on it.
4 Push the new fuse firmly into its slot in the fuse box. Switch on the circuit concerned. If the new fuse blows immediately, there's a problem.
Don't try to 'cure' a persistently blowing fuse by fitting one of a higher rating than that specified, or bypassing it with metal foil or wire. Serious damage or even fire could result.
- It's a good idea to carry a few spare fuses in the car - they are usually included in a spare bulb kit.
- One fuse sometimes protects several circuits - for example, the interior light may be on the same fuse as the clock.
- If you don't have any spare fuses, in an emergency you can 'borrow' one from a non-essential circuit such as the heated rear window or the cigarette lighter.