I'm dealing for a customer with a WHITE WESTINGHOUSE fridge/freezer (RTD 18WWCW5 ser: BA 81817611) this is probably an export model made by White Consolidated Ind in Cleveland Ohio.
The original complaint was that vegetables were freezing in the food compartment probably because the thermostat was stuck and the compressor running all the time. I bypassed the thermostat and connected the fridge with a timer socket running 45 min on 30 minutes off and was good for 3 weeks.( I did this because I knew it would take a long time to get a new thermostat) Now the evaporator was icing over and I went over twice in a month to do a manual defrost. Both times when I pressed the defrost button on the card it defrosted, so heater + defrost stop OK.The second time I put the original thermostat back in because it operated OK when I sprayed with liquid freon and I also gently tapped the relay on the ADC-card.The fridge was fine for a month and now the thermostat is stuck once more,Customer put timer back in socket and now there is a defrost problem again. Is there a relation between thermostat and ADC card. I finally got the new thermostat but I am hesitating to put it in because if there still is a defrost problem once I have opened the thermostat I can not return it!!
Here are my questions:
1. What controls the defrost frequency on this ADC-card(thermostat,light in food compartment or other)
2.Can I replace the ADC-card with a regular mechanical defrost timer(25 min every 6 hours) or an SUPCO defrost timer with adjustable time and defrost frequency
3. Is there a logic explanation that there is a defrost-problem ever time the thermostat is stuck.