Hi, came across a freezer with a Dixell XR60CX controller. Condensor is icing up as the defrost is not working. Uses electrical defrost heater, and when defrost is on there is no power coming out defrost wire from controller. Thing is electrical drawing for controller shows 8 connections. 1=power in, 2=fan motor, 3=compressor, 4=power in, 5=neutral, 6=power to switch defrost, 7=defrost output and 8=NC.
There is nothing connected to 6, so wondering if I can bridge power from 4 to 6 without damaging controller. Other engineer fitted new controller so I dont know what happened with connection to 6. Either this needs power or power goes through controller and it is faulty.

Any ideas,