What would be the problem when my side by side refrigerator is not freezing on the top of the freezer but on the bottom about half down

Good day,
Two possibilities.
1. Circulation fan motor behind the rear panel of the freezer compartment not running.
2. Auto defrost system has failed.
If you see a frost buildup on the rear panel in the freezer, remove the rear panel and check the coils for excessive frost buildup.
The defrost system is made up of three parts.
1. The main heater, which is mounted on the evaporator, and looks like the bake element in an electric range.
2. The defrost thermostat ( a small round disk mounted on the top of the evaporator).
3. The defrost timer (either a mechanical or electronic model) located in the fresh food section.

To test the continuity of the main heater you would need a ohm meter and have a working knowledge of electrical. Applies to defrost thermostat as well, but it can be tested only when it is cold.

Locate the complete model number and go here to see the layout.

http://www.appliancepartspros.com