USUALLY the brake lights and the turn signals on the rear of the truck use the same filament in the rear bulbs when turn signals are installed. IF (big if) the rear turn signals work, but the brake lights do not work, the likely point of failure could be either the brake light switch or the turn signal switch.
If the brake lights AND the turn signals don't work the failure is more likely in the turn signal switch.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
| 
