Why does flasher click when blinkers are not on?

are you sure it is the blinker? The reason I ask is I had a similar clicking noise coming from under the dash near the center console. Turns out that there is a switch under there that controls the vent door. On my 03 the switch was going bad and it would click almost identical to the blinker. The next time you hear the click try pushing the recycle air button on the a/c unit off and on several times. It worked for me. I must tell you though that my recycle air doesn't work now which leads me to believe that the switch eventually broke completely. Tweek