Where is the brake light fuse for 2003 ford mustang

SOURCE: A diagram of a 2003 Ford Mustang interior fuse box?

Fuse Box Diagram

Circuit Schematic

I trust that these are what you are looking for, they are screen captures of the requested information right from Ford.

SOURCE: mustang brake lights dont work

this car has a brake light switch on the pedal check for power in and out. if in and not out change switch. also I believe their is a relay under the hood . then check to see if the multifunction and hazard switch control brake lights i cant remember if they do like gm's but i am also almost sure they do the multifunction is your turn signal wiper arm that goes into steering wheel . after you check the brake switch and relay have some one jiggle the hazard and multi while pressing the brakes see if they come on. you can call ford and ask them about the multi and hazard .

SOURCE: A diagram of a 2003 Ford Mustang interior fuse box?

here you go
https://www.fleet.ford.com/maintenance/owners_manuals/default.asp

SOURCE: A fuse box diagram

Hi,this is the central fuse box diagram for your 20003 ford mustang.