Could be turn signal flasher
Bad flasher?
most likely a bad turn signal flasher
signal lights not working.
Your taillight is burned out.
Bad turn signal flasher?
Possibly a defective Flasher Relay. Replace it. Can also be a turn signal switch going bad. You can try cleaning it with a spray electronic cleaner.
A signal light that is not working.
Either hand signal or check and replace your fuses and turn signal bulbs.
If your hazards still work, most likely your turn signal relay needs to be replaced.
Yes, they both work off your signal light arm, therefore they share wires. I have the same problem on my '93 Silverado, although I have not investigated it yet. I think you're going to have to take the steering column cover off and investigate the wires entering the signal arm. Look for shorts or worn wires or loose connections. Good luck, Jim.
Left sinal not working in trailer hook up ?
Signal LOSS per 100 feet.