also seems like the freezer alternated between cold and warm. there doesn't seem to be any frost buildup on back of freezer wall. i've done a bit of research and it seems like i need to check the defrost timer and the defrost limit thermostat.

1. from looking at a parts diagram, i don't see any mention of the defrost limit thermostat. there isn't any? where is it located?
2. i presume that the defrost timer is in the control section in frig section where temp is set. is this correct?
3. the evaporator is behind the freezer rear wall? how do i get the freezer rear wall out? any tips on doing this? or is there an easier way to get to evaporator and defrost limit thermostat?
4. anything else that i should check?