1994 chevy silverado Brake lights not working

[kettle]

1994 chevy silverado p\u brake light over cab is working as well as all other lights and turn signals. Only the brake lights on the rear are not working. Already checked fuses and pedal switch and relay on the firewall. Could my problem be in the turn signal switch and if so how do I test mine? How does the circut run thru the turn signal switch? Any help or information will be appreciated. 5.7 v8 automatic 4x4........Kettle

[kettle]

Found the problem. Broken wire on plug from steering column. Made repair, brake lights work now. Thanks  Kettle