i just bought a 2002 f150 4.2 v6 and my daughter and i done a complete vi to make sure everything worked and i had ALL lights,a few days later my buddy followed me home from work and informed me i had no break lights.I have turn signals,flashers and everything else but no break lights.I checked and changed fuse and i also put a new break light switch.what else could be rong??

 

Might sound like a dumb question, did you move the tilt on the steering wheel column ?

The wiring harness some times can be stretched tight and moving the steering wheel column can pull the connector apart, causing the stop lamps to no longer work, when that section of the connector pulls apart.
- Quick test: the CHMSL ( Center High Mount Stop Lamp aka 3rd brake lamp ), does it work ?

Did you check with a meter, while installed, fuse # 13 ?
- This is what powers the Brake Pedal Position switch ( aka brake light switch )

If memory serves me correctly on the 2002 the same circuit for the Brake Pedal Position switch is also the shift interlock switch, so unless you could not shift out of park while the truck was running, this was OK ( and CJB fuse #13 to is also good ).

Check the CHMSL and if that is working ( if not, check that the bulb is not blown ) next is to try the steering wheel column in a few positions.

If not, it is time to remove the MFS ( Multi Function Switch / turn signal lever ) to test it.