Saab: turn signal failure, saab aero, signal failure

Question
QUESTION: left position light failure but all lights and signals work. whats wrong?

ANSWER: Rick:  My understanding is that all other lights (headlights, brakelights, parking lights,instrument lights, etc. work). Please verify.  How about the right turn blinkers?
 Also, can you tell me the year and model of your vehicle?

 In general, the most likely cause, if all of the above assumptions are correct, is the blinker light switch mounted on the steering column.

    Hope this helps,
         Jerry


---------- FOLLOW-UP ----------

QUESTION: the left blinkers work as well as the right .this is a 2007 saab aero .this was the message that comes on every time we start the car .

Answer
Rich:

 AHA!  Now I think I underestand...all lights work, but an error message appears upon startup. In general, then I can only say that the sensor circuitry for signal light integrity is at fault.  It could be that one of thre bulbs has aged and the sensor "thinks" its faulty. Also, some corrosion/high resistance connection in the wiring could also be a cause. (This is all speculation since as stated in my profile, my hands on experience to the earlier 900's only.)\
         Hope this helps,
         Jerry