No brake lights or turn signals ford f150?

If You don't have any brake lights or working turn signals on Your Ford F-150, the most likely cause is going to be that the switch is bad. Try disconnecting Your brake light switch and connecting the two wires together. The next possibility here is going to be a blown brake relay. This is a 15A fuse, and the slot is labeled "Brakes/Signals" in Your fuse box. This should be Your neXTStep to check. You should also check the electrical system, if You still haven't found the culprit; this could be a short, preventing it from properly working. Obviously, You've verified that the bulbs in Your lights are all working: If someone's smashed them out, You won't see any illumination no matter what switch You pull.