Whirlpool Refrigerator not cooling.. Fan Problem?

My refrigerator is just under 2 years old. Whirlpool top freezer. I removed the back panel of the freezer and the coils are not overly frosted. The fan that blow the air into the fresh food compartment does not seem to be turning on. Any ideas on how I can pin point this problem?

Thanks

been defrosting for a couple hours to see if it helps. I assume it is something with the fan motor but am not sure where to start with this

I would remove the evaporator fan and stick 115 volts to it if 115 volts is printed on the motor housing. If blown open, order one here 2214986. If ok, you will probably need a meter to find the problem.