I have tried to unclog the defrost drain and that didn't help. After defrosting the unit, the problem returns. The unit seems to run excessively with minimal contents in fridge and freezer. The unit does shut off but it seems to run a heck of a lot more than it is off. I have the unit disassembled to check for clogs in defrost tray underneath the freezer. Is it possible that I have a bad thermostat? I'm assuming the one is mounted on the coil and the fridge thermostat is the control knob...yes? Could one or both of these be bad? Thanks.