Kenmore refrigerator cools fine, but there is a clicking noise coming from it like it is trying to cycle or turn something on. it is old but works fine, but i wanna find out what this noise is before it is too late. there are no issues with cooling, frost, or anything else. only the clicking noise. it only clicks then about 5 seconds later, it clicks again like it is turning something off. I know nothing about appliances but am competend with a multimeter since i have worked on cars. please tell me where to start. any help would be appreciated.