@Scott Johnson use a “digital “ thermometer to check the temperature at the ice maker. You can pick but a “digital “ thermometer almost everywhere for under $20. The temperature at the ice maker must be below 9*f . The I/M will not advance if it’s 10*f or warmer. If the temperature is below 9* a gear or switch in I/m head could be bad. Dirty condenser coils is usually the problem. The condenser coils MUST be cleaned at least once a year, more often if you have indoor pets. Condenser coils are underneath the refrigerator. Unplug the unit, remove the rear access panel and vacuum all the dust out.
This comment does not apply to a Samsung french door refrigerator with the ice maker located at the top left in the refrigerator section. Google Samsung Class Action Suits if you have a Samsung ice maker issue.