A freezer motor that is constantly running without stopping can be caused by a few potential issues. These include:
The thermostat has been set too high, causing the appliance to run continuously in an effort to cool down the interior.
The condenser coils are clogged with dust or dirt, preventing the appliance from cooling properly.
The compressor has malfunctioned and is unable to effectively regulate temperature.
There is a leak in the door seal, allowing cold air to escape and forcing the appliance to work harder than necessary.