Check the wiring. Probably got a short. It could be a short, however, if your tail lights are illuminated, then you might rule out a short. You might also check your fuse for the brake lights. If the fuse is good, then you should check your brake light switch. It is probably a small box-like object attached to the brake pedal arm. To check the switch, you will need a circuit tester or testlight. The switch has two wires. One of the wires will be hot (have current all the time). Locate the hot lead. The other side should not be hot. Now, depress the brake and check the other side. If it is now hot, the brake light switch is good. If you have tail lights, and if the fuse is good, and the brake switch is good, then the problem may be in your turn signal. Hopefully, you have a blown fuse.
Blown fuse, bulb, or bad brake light switch.
Check the bulbs, fuse & brake light switch on the pedal.
Check the bulbs - they are doubloe filamented with the smaller being for brake/turn signals Check the fuses
burned out bulb, blown fuse, wiring
Bad switch, bad relay, short to ground in the circuit.
Brake Lights not Stop Lights. Check your Fuses then the Bulbs. Hope This Helps.
The brake lights in your 1983 Nissan pickup truck are controlled by the brake light relay switch. When the brake light relay switch malfunctions the brake lights will stop working.
If the turn signal is working it's either the brake light switch or the turn signal switch.
if turn signals are working , and brake lights not working, i would replace the stop light switch on the brake pedal
Blown fuse Bad bulbs Defective or mal-adjusted stop light switch
Check your brake lights and see if they are working. Ford has it so if your brake lights are out you can not shift out of park.
A malfunctioning brake light and flasher relay switch will cause the brake lights and flashers to stop working. The relay switch can be found below the dashboard on the drivers side of the passenger compartment.