It could be your flasher unit. It is easy and cheap to replace. Depending on your vehicle it could be under the dash or on the fuse panel.
Check the fuses and the flasher unit.
You could have a lose wire in the stering column.
For most vehicles the hazards and signals are two separate circuits, they have separate fuses and separate flashers. Check your signal light fuse and signal light flasher.
not fuses or relay?
It could be the turn signal bulbs, some vehicles use separate bulbs for the hazard and turn signals. It could also be a bad switch or wires for the turn signals.
Check the fuses first of all. I think the Durango has two flashers as well, one for the hazards and one for the signals so it could be a bad flasher.
replace turn signal flasher
Change front light bulbs
If the turn signals are not working properly on a 2002 Chevy Venture and the fuses seem to be alright, check for burned out bulbs in the turn signals. Also, check to make sure the turn signal flasher is working properly.
There are two flashers, one for the hazards and one for the signals.
I sprayed WD-40 into the blinker hole on my steering column of my 1985 Sentra and they have worked ever since.
Check your fuses. Sometimes a fuse can be the cause of a seemingly difficult problem.