Brake Lights wont shut off

SOURCE: Brake lights

I have a 98 and had the same problem just today, I found the problem by looking up where the pedal goes to and you will see two switches that the pedal hits when released, its the switch on the left side of the car, you will notice two (well one is prolly missing since the lights wont go off) blueish rubber pads on the brake pedal that hit the switches. since the one that goes to the switch to turn the lights off is gone go out and buy a small plastic body push screw to insert in the hole the old pad was in. there ya go all fixed

SOURCE: brake lights dont work

check brake light switch..under dash up at top of brake pedal.with wiring harness on one side and spring loaded pintle on other that reads when brake pedal is applied

SOURCE: FORD BRAKE LIGHT

check the connector at the brake switch located on the brake pedal lever arm if it is ok it is most likely a faulty switch

SOURCE: brake lights not working

If the 3rd brake lamp is working then the problem is the multi-function switch on the steering column.
To replace it remove the lower trim around the column and you should be able to access both screws to remove it.If you have to remove the upper trim around the steering column to get to the top screw the you will have to remove the lock cylinder. To do this turn lock cylinder to on position then look under the bottom and you will see a small hole.Insert a pick or screw driver into the hole and press button and pull the lock cylinder out.

SOURCE: 98 Ford Explorer No Brake Lights

There should be some adjustment on it, if not replace it, it's about a $12 item.