Freezer too warm

Moved this one to garage to make room for new fridge. Was working fine in house. Now fridge section seems fine, maintains 35-36 deg F. Freezer is erratic. Can get it down to 0, but seems to slowly works its way back up - is currently 30 deg. Almost nothing in it, so air flow inside is OK. Even went so far as to remove icemaker to make sure warmer not running constantly.

Any ideas?