Fuse for brake lights blew so I replaced it, tapped the brakes the lights worked. I then started it up tapped the brakes again no lights. Checked the fuse. It was blown again. Also when I tap the brakes my headlights dim a little bit. Any ideas?
So first check the bulbs, swap them if necessary just to test.
If it still blows then there must be a short somewhere and you have to inspect the wires for chafing and damage - only needs a small hole & connection to blow a fuse...
One that took us a long time to find was a broken seat spring poking into a wire to blow the fuse. Only happened when the owner sat in the seat as it compressed so much: overweight was an understatement.