I am having a random problem with left turn signal on my '06. The signal works, both front and rear bulbs flash, however, if they flash for more than 10 - 15 seconds, they suddenly start flashing very rapidly for several seconds, then they quit for a second, and then start flashing at normal rate. Then it will repeat the cycle. BTW, this is the second turn signal switch that as been replaced on this truck in the 5 years that I have owned it. There was extended warranty on them which tells me this must be a high fail item. Anyone else had this issue? I have read a lot of posts on this forum concerning turn signal issues.