What year is the Ford Explorer ? There could be a separate fuse for the lower
brake lights
check your bulbs
If the fuses and bulbs are okay I would blame the signal switch assembly. They call it a multi-function switch these days.
check that you have double filament bulbs in tail lights
Have an electrician check the wiring that goes to the brake lights in the trunk of the car.
Check the brake light switch.
Check fuse Check stop light switch-usually located at the upper end of the brake pedal. May be out of adjustment, or defective
brake light switch, it is typically located above the brake pedal somewhere on the brake pedal arm
check for bad switch under dash above pedal arm, generally fail after 75,000 miles
fuse, bulbs
AnswerThe bulbs for the brake lights are usually separate from the normal tail light bulbs. Check and replace the brake bulbs first, and if they are still not working examine the fuses, switch and wiring.
Check bulbs, fuses and brake switch in that order.
Possible bad switch on the brake pedal? When you push on the brake pedal, it activates a switch, that switch turns on your brake lights. If the bulbs and fuses are ok, check the switch with an ohmeter.