Turn Signal Light

[agoh@sprynet.com]

My front left turn signal light is not working.  

The turn signal light doubles as a marker light and this function works.  I 
checked the bulb and it's fine.  But it does not flash when the turn signal is 
activated.  When I activate the turn signal, the flasher blinks at a faster rate 
than the right signal lamp.

What should I check?

Any advice will be much appreciated.

Thanks,
Andrew
1971 Automatic Fastback (Seattle)