you need to change the flasher can for the signal lights
An indicator relay, also known as a flasher relay, controls the timing and rate at which turn signal lights on a vehicle flash. It is an essential component in the turn signal system, providing the necessary signal to the bulbs to blink in a specific pattern to indicate a turn or lane change.
turn signal relay is bad
Buy a "highway" turn signal flasher
Are both lights coming on and staying on? sometimes when a light is out on the front or rear the lights just come on and will not blink.
burnt fuse. check the fuse box
You either have a bulb burnt out or the turn signal flasher is bad.
That can happen when there is a bad ground to one of the lights.
Maybe a short somewhere...did you replace the flasher unit? No - it was blinking spuradically(?) - now I have to blink it manually and it won't blink at all with lights on.
Check electrical grounds
If the lights blink fast on either side of the car then this means you either have non-factory bulbs in the car or you need to replace your blinkers because one of your lights is out.
If you mean that the arrow inside the dash turns on and stays on then your problem is one of the left side turn signal bulbs. Test by turning on your four way (hazard) lights and observing all lights. The one that does not flash is the bulb that needs replacing.