If the brake lamps and the signals are all not working, you most likely have a faulty turn signal switch. The brake light wiring passes through the TS switch, and uses common wiring to the rear of the truck.
First, check to make sure the 40 amp fuse in cavity 3 of the underhood fuse block and the 15 amp fuse in cavity 6 of the interior fuse block are not blown. If the fuses are OK, check for power coming into the turn signal switch on the red/gray wire (which passes through the flasher) and power coming out of the switch (dk green/red to the left rear and brown/pink to the right rear). If you have power in and not out of the switch when it is activated, the switch is faulty and will need to be replaced.
the switch is part number(NNN) NNN-NNNNand retails for about $102.00 at any Dodge dealer parts department.