The 2 most common part(s) or condition(s) which cause the symptom Dishwasher won't dry dishes are listed below starting with the most likely. Check or test each item and watch any available videos.
RepairClinic Item # 824329
Many dishwashers have an electrically controlled vent damper that opens at the end of the cycle to let out the hot steamy air. If the dishwasher won't dry dishes this vent may not be opening properly.
RepairClinic Item # 1475227
There is a heating element near the bottom of the dishwasher to dry the dishes. If the dishwasher won't dry the dishes the heating element might have burned out. The heating element can be checked for continuity.