Six things will affect 'insufficient cooling on both heat sources'
*Leveling .... off level operation can stop the coolant flow thru cooling unit
*Ventilation .... insulation has fallen down, airflow/draft is obstructed
*Thermostat .... failed thermostat can not regulate fridge temps (inside the food compartment with senor wire ---part of lamp/door switch assembly)
*Air leaks .... fridge door seals bad
*Cooling Unit .... obstructed/blocked ---- coolant has been overheated causing crystals to plate out on the inside of tubes (Cooling Unit DEAD)
Here is the Service Manual for the 3604/3804 fridges
http://techsupport.pdxrvwholesale.co...ice-Manual.pdf