At some point, you’ve probably heard someone mention that their car has ‘blown a fuse’, the reasons why can often be mystifying. This week we’ll break down what fuses do in a car and how you can best deal with a blown fuse.
Fuses are an integral part of a car’s electrical system, and help protect the various electrical components fitted to your car. With cars becoming ever more complex electrically, however, the number of fuses used has also increased. With this has come more confusion over which fuse could have blown and why.
Fuses – What Do They Do And What To Do If They Fail
- How does a fuse work?
The main part of a fuse is a thin wire or metal strip designed to melt at an electrical current draw slightly over the standard draw of the electrical component(s) and wiring it is protecting. When this metal strip or wire melts, it does so very quickly, which is why you can see them flash and pop, hence the term ‘blown’.
- How do I know a fuse has blown?
The first obvious sign is that the equipment you were trying to use, no longer works. You may also find that a few other items may not work either and that is a very clear indication of a fuse being blown. Many circuits use the same fuse to protect them, so for instance, if your radio, interior light and electric mirrors no longer work, it could be the fuse that covers them.
- How do I find out which fuse has blown?
The best place to start is your vehicle’s handbook, if you still have it. There will be a section on the fuses and what they cover. It will also tell you the location of the fuse box and also, more importantly, which fuse it is! Most fuses will be colour coded. The most common ones are 5A orange, 10A red, 20A yellow and 30A green. When you pull out the fuse, you should be able to see if it has blown by the broken strip or even a blackened burn mark where it has burnt.
- Do’s and Don’ts
- Only replace a fuse when the equipment, and ideally the ignition, is switched off.
- If there are a number of items that are protected by one fuse, only switch them on one by one. Otherwise, if it blows a second time, you will not know what item is causing it.
- Never replace a fuse with a higher rating than the one you are replacing. Equipment may be damaged, or in the worst-case scenario, the wiring loom can melt instead which can cause a fire!
If you are unsure what is wrong with your car’s electrics or need help finding out why a fuse keeps blowing, then book a FREE phone consultation with one of our experienced in-house mechanics or place a booking online for a diagnostic inspection.