The break lights in the rear stay on, even when truck is off.. .

With the pedal in the up position, Is the button released and not touching the pedal http://partimages.genpt.com/largeimages/51030.jpg if its not adjusted right and the button is depressed the lights will stay on. If that doesn't work try unplugging the stoplight switch and see if the lights go off, If they do and its adjusted properly you might have a defective stop light switch from the parts store

i agree. adjust the switch Roy