Hi, Frank.
The defrost termination sensor should be the cause of your woes - can go bad intermittently. and make sure the new fuse does not get positioned too close to the heater

Quote Originally Posted by frank View Post
Had to strip down the Fridge section again at the weekend to carry out a manual defrost with the trusty hairdryer - (well, I don't need it any more for my head ).

Found that the inline thermal fuse had blown again, preventing the defrost heater from being powered up.

I find it strange that the thermal fuse is rated at 5A, has a circuit fail temp of +73C and it is the second one to go open circuit. I can't imagine that the top section of the evap where the fuse holder is attached has reached +73C or that the fuse has overheated so much. The defrost heater is rated at 120W and pulls 0.54A.

Anyone have any suggestions on an alternative failsafe to replace the inline thermal fuse?