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Just correcting a few minor factual errors...

The rating of a fuse is the current it will nominally carry in steady state without blowing. In addition to the steady state current, there are also the different variants; normal, fast and anti-surge. These latter charateristics determine how quickly the fuse blows in an over-current situation. Low voltages used on cars tend to mean very high inrush currents, particularly on lamps. The fuses don't lend themselves to traditional anti-surge construction so tend to be a little over-sized.

At 40-50% over nominal current, it could take a minute or two to blow.
At twice nominal current, the fuse will blow within 5 seconds max.

Also, fuses aren't necessarily rated correctly for the wiring they are intended to protect. For example, the wiper system has a 30A fuse on it. Whislt the primary feed from it is in 2.5mm wire which is rated at 30A, there are many sub-circuits that are in 1.5mm, which is rated at something more like 18A max.

To answer the domestic fuse question, they have to be in very robust packing which precludes the use of any obvious optical indication.

Alternators don't generally have voltage surges but any device being fed by it can have a current surge.
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