Where is the brake fuse on a Mustang?

There isn't a single "brake fuse" in a Mustang. The braking system relies on several electrical components, each potentially protected by its own fuse or circuit breaker. These components include the brake lights, brake shift interlock, and potentially ABS (Anti-lock Braking System) modules depending on the year and model.

To find the relevant fuses, you need to consult your owner's manual. It will have a fuse box diagram showing the location of fuse boxes (there may be more than one) and which fuses control which circuits. The manual will also usually list the amperage of the fuse so you can replace it correctly.

Without knowing the year and model of your Mustang, it's impossible to give a precise location.