1990 Chevy Lumina turn signal

Sounds like you could have a bad turn signal switch here is the instructions on how to change it.

1. Disconnect battery ground cable.
2. Remove nut retainer and jam nut, then the steering wheel.
3. Remove turn signal cancel cam assembly.
4. Remove hazard **** screw and the hazard warning ****.
5. Position turn signal switch so that turn signal switch screws and housing screw can be removed through openings in switch.
6. Remove housing screw and the column housing cover.
7. On models with tilt columns, remove shoe pin retainer cap.
8. On all models, remove pivot switch screw and the pivot and pulse switch assembly.
9. Remove turn signal switch screws.
10. Remove wiring protector from opening in instrument panel bracket on jacket assembly and separate from wires.
11. Disconnect turn signal switch connector from ignition and dimmer switch assembly connector.
12. Disconnect 17 way lock from turn signal connector.
13. Using terminal remover tool No. J-35689-A or equivalent, disconnect wires on buzzer switch assembly from turn signal connector.
14. Remove turn signal switch assembly from column.
15. Reverse procedure to install, noting the following:

1. Torque turn signal switch and column housing cover screws to 35 inch lbs.
2. Torque pivot switch screw to 20 inch lbs.
3. Torque hazard **** screw to 7 inch lbs.
4. Torque jam nut to 30 ft. Lbs.