...And encouraged/recommended to use higher voltage rated fuses in automotive applications!
As voltage increases, so does resistance of the fuse material as it heats up. The fuse will be accurate to it's rated voltage, in your case, it will be accurate up to a 250 volt current path...
That doesn't mean it will be less accurate at lower voltages.
The 250 volt mark is about standard (so it can be used in 220/240 volt hardware).
Anything under 250 volts is considered 'Low Voltage' in most electronics circles, that's why the 250 volt rating.
Also, most of the worlds electrical utilities supplies are under 250 volts, so the same fuse can be sold in most countries and do the job just as it is.
Your fuse will be accurate in your 12 volt system, no problem.
"Maybe a diode?"
Again, dale doesn't have a clue what he's talking about.
DO NOT attempt to substitute a diode for your circuit protection!
Since discovering diodes in one of my posts, and finding one at Radio Shack, dale has had a fixation with diodes. Don't ask me why.
Probably because they have 'Magical Powers' he doesn't understand.
dale got spanked here too often, so dale frequents another bbs now...
dale has said in writing he wants to ruin this bbs because he posts on another bbs now, so he's trying to get you to melt your rig down.
Not very nice of dale, and the moderators should ban him for trying to get you to damage your vehicle...