Fuse Amp Question

Hi all, please don't ask why, but I have my rear brake light wired directly to the battery with a separate line and an inline 15 amp little auto type fuse. So, it draws battery juice only when I put the rear brake on.

That little fuse blows every couple of weeks! I just guessed a 15 amp fuse would do it, wrong? Should I put a bigger amp fuse in there, how much does it draw?
Thanks for any comments

highdesert said:

That little fuse blows every couple of weeks! I just guessed a 15 amp fuse would do it, wrong? Should I put a bigger amp fuse in there, how much does it draw?

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Watts divided by Volts = Amps.

15A is a higher fuse rating than should be necessary for one brake light = 21W(UK) (US 23W?/25W?)/12V = 1.75A (23W = 1.92A, 25W = 2A) ) so a 5A fuse should be adequate.

If a 15A fuse regularly blows then I expect there is an intermittent short somewhere in the wiring, switch or lamp unit?

Maybe stop lamp switch leads are being rubbed by the chain? The rear brake switch wires are the hot lead to the stop lamp and it runs close to the chain on mine.