Passenger side signal indicator in the dash started blinking fast out of the blue. Figured burnt out bulb on passenger side. Front turn signal bulbs not blinking. Great one or both burnt out. Checked both bulbs, both looked great. Swapped bulbs from driver side and those bulbs didn't light when in the passenger side but bulbs from passenger side when placed in driver side worked. So then I tried different flasher. No change, however I did notice that depending on how I move the 4 way flasher switch on steering column sometimes only the drivers side indicator flashes on the dash but all the lights except the front passenger turn signals are flashing. Then when I try the switch a second time both turn signal indicators in the dash work..

 

I had a Chevy Blazer that did the same thing and, believe it or not, there was a bulb in the rear that was bad.

 

I don't see any other lights burnt out.

 

It is probably the socket for the bulb.

 

Going back through troubleshooting list and a lot of jiggling it was the sockets.