79 Ford Ranchero brake lights not working
I have a 79 Ford Ranchero so far I've replace
the brake light switch on the pedal in the
Flasher solenoid in the fuse box any other
Most common with thee old Fords is the turn signal switch itself, it cancels the brake light on either side when the turn signal is used. Also check the 4way switch, sometimes it can get stuck between modes and cancel the lights also, try cycling it a few times and see if you brake light come back, if not then it's time for a turn signal switch.
Ever light works but the brake lights
You do have power at the brake light switch? And when the pedal is pressed it goes through the switch and out the other connector right? If so, turn on the 4 ways and step on the brake pedal, the 4 ways should stop flashing and stay on steady, check both front and rear lights, if they don't repalce the turn signal switch assembly, if they do then you have a wiring problem, possibly in the in the steering column, or main harness through the front bulkhead.