Originally Posted by remmons
As crazy as this sounds, your problem may be in the turn signal switch itself. A contact might have worn or a spring may have failed. The only drawback is that you have to replace the entire assembly as that it is a unitized unit that also contains your headlight switch and the wiper switch(s). You will have to remove your steering wheel, but you have to follow the instructions on disarming your airbags first.
No I do not think it is the Multifunction Switch as the Hazard Flasher should work even if you pull out the Multifunction switch.
To the OP:
I would first suspect the wiring coming out of the Hazard Switch to the Left turn signal, the Dark Green/Red wire on pin 7 of the Hazard Switch/Combination Flasher. Put a meter on this pin 7 and check if you get +12 volts there when the Hazard switch is pressed or when the Left Turn Stalk is activated...if +12 volts is there then there is a break in your wiring coming out of the Flasher Switch.
If +12 volts is not on this pin seven then the Hazard Switch is defective.