I have a Kenmore Coldspot side by side. It's about 24 years old.

The freezer gets outrageously cold, and the refrigerator will not go below 49 degrees. Currently, the freezer shows -18, and the refrigerator is 49.8.

I've disassembled the vent at the left top of the unit, so nothing is blocking the cold air from the freezer. It seems to develop frost on the freezer side.

I've cleaned coils and anything I could get to.

I'm at a loss.

We've already purchased a new unit, but I would like to fix this one. It will be two weeks or so before the new one comes in.

Does anyone have any ideas what the problem could be?

Thanks
Charles