if it only the drivers side one that's not working it would indicate that its not a fuse as both lights are normally on the same circuit check for a break in the cable leading to the lamp and make sure the lamp is well earthed
AnswerComment to above answer, that is actually wrong, as in the Ford focus(all years) the drivers side lights and passenger side lights are an different fuses, so a brake light out could be a fuse. but always check the bulb first, its usually the safe bet, and as for the fuse symbol, i suggest either looking in the owners manual for the fuses or get a manual for your car(i.e chiltons)how change brake fluid . i have ford focus lx 2000.ans how change air filter.
Master cylinder mounted on the firewall, drivers side.
The brake light switch is located under the dash. It is connected to the upper arm on the Brake pedal
you bought one of those? what a weirdo
Fuse #54 - 15 Amps. Fuse panel on lower left of drivers side dashboard. If you're having troulbe with both your brake lamps not illuminateing also check the brake switch (mounted close to the top of the brake pedal arm). It's possible that it might have failed.
By the fire wall on the drivers side, has a yellow cap
7mm
Under dash, drivers side, above parking brake.
On a Ford Focus : The transaxle ( transmission ) is in the engine compartment , bolted to the engine , on the drivers side of the engine compartment
It gets added to the master cylinder located drivers side of the firewall
On the drivers side firewall. Underneath the brake fluid reservoir
In North America ( DOT 3 brake fluid ) meeting Ford specification ( ESA-M6C25-A )