use a test light or a multimeter to check for power at the tail lights, check bulbs.
well ,it could be several things, i have heard of things like a varmit or animal eating away at the wires of a car or a shorted-circuit, blown fuse or fuse circuit.. but most often it as simple as a brake-switch gone bad...it is located most often just under the brake pedale in most vehicles. and usaually is less then $10 simple to replace. The BIG question, does your third brake light still work? If it does, check your turn signal switch. Primary brake lights are wired through the turn singal switch in order to cancel the break light when a turn singal is activated. I have never replace a turn singal switch on a Ford Focus so you should consult a repair manual on the proper procedure of replacing this switch, if it is deemed defective.
If the fuses and bulbs are okay I would blame the signal switch assembly. They call it a multi-function switch these days.
the brake switch at the pedal is stuck or out of adjustment.
Brake Light switch works without the ignition on. unplug the brake pedal switch and check to see if the brake lights are still on..switch could be defective
The turn signal switch overrides the brake light circuit while the turn signals are on. If the switch is damaged or worn out the brake lights won't work.
Yes.
The most likely cause is a bad brake light switch (if none of the brake lights illuminate) but if its only one of the brake lights, try changing the bulb. Even if they still work as running or turn lights because they have a double filament and may still work partially, but not as brake lights.
The rear lights of your car will still on even if your car was off because the switch was turned on and it will still remain on until the battery's out. Another possibility, if the headlight switch is off and the ignition switch is off, the brake light switch may be out of adjustment or broken and what you're seeing is the brake lights on.
brake switch located on the top of the brake pedal
Check the petal and make sure that the plastic part that touches the brake light switch when the petal is in contact with the brake light switch is still on the petal, if it is missing you will need to replace it, so the petal will make correct contact with the brake light switch.
Assuming you mean brake lights, the brake light switch is broken or out of adjustment.
You may want to start with the brake fuse. If you still have turn signals and lights. you may also want to check the brake electical relay switch in the relay box Check as well the brake switch located at the brake pedal.