Why are my brakelights not shutting off

what about brake light switch which should be behind brake pedal. Check also the bulbs if are working both sides.

There are 2 switches at the brake pedal. 1 is the brakelight switch & the other is the cruise disengage switch. Possibly 2 faulty switches but you should diagnose first. Check brake light fuse, then disconect brakelight switch, bridge plug brakelight switch if lights come on = faulty switch, check globes

Check the fuses..If ok ,,then most likely the signal switch..Your brake light circuit runs through the signal switch as well..Get someone to watch your brake lights to see if they come on..Now push the brake down and move your signal switch around and see if the brake light comes on intermittently..If so its definetly your switch

check voltage from brake switch to signal light switch, if good the the signal switch is probably bad

Did you check the brake switch adjustment.
Next to and behind brake pedal arm

1. Check the fuse make sure it is not busted and also use a designated amp only.
2. Check the bulb and the wires also.
   

brake switch under the brake pedal

check the feed to your brakelight switch
using a long,long piece of #18 gauge wire connected to the + (positive) battery post/cable then to the brakelight switch press the brake pedal if the brakelights come on run a new supply wire to the brakelight switch

Pull up on Pedal (BRAKE) Pedal if that turns them off try to ReAdjust Brake Light Switch. Or Replace it

When this happens the problem is most likely the multi-funtion switch aka turn signal switch. Check to see if the 3rd brakelight comes on when the brake pedal is pushed. If so replace the MFS. The 3rd brakelight in late 80's fords bypasses the turnsignal switch.