Answer Graeme, you may want to check the freezer evaporator for an excessive frost build up. If there is excessive frost clogging the evaporator, then this will cause air flow to stop. If there is excessive frost, then you will want to test the defrost heater and the defrost sensor/bi-metal. The heater should have a resistance reading between 16-22 ohms and the sensor/bi-metal should read continuity. If either of these fail, they would need to be replaced. Read More... Answered by AppliancePartsPros.com | Saturday, April 27, 2019