Mel, or Ted, or whoever you are, let me share my limited experience with said Amana (nee Maytag).

If your refrig is the same or similar model to the ones typically installed in Libertys it is a fairly simple device. Your symptoms sound like mine so I will give you the short version of what was a saga. The intermittent operation is what I had and I had two problems. The first is simple to diagnose. When the compressor is running you should also have a fan in the freezer side running at the evaporator coil area. That fan is what is distributing the air within the freezer, blowing it across the coils, and when it is not running the lack of air circulation does not allow the air surrounding the contents of your freezer to cool down sufficiently. That can be checked and replaced with the refrigerator mounted in place.

I fixed that and the SOB still gave me sporadic operation.

I pulled the refrigerator out (build a 3" high platform to roll it onto) and then slide the whole thing where you can get at the rear. In the lower rear is another fan. This fan cools the condensing coils. On mine it was intermittent, and so when we were driving the refrigerator worked perfect because the vibration of running down the road was enough to jar the fan and get it spinning. When we were parked it would operate only occasionally. Replacing that did the trick.

I had previously replaced the evaporator coil, but if that has a leak or there is a leak anywhere in the system it will not work at all. Your on again, off again operation suggests the fans may be the culprit.

You can get parts at a Maytag repair parts store. They are available despite what you read if you do an online search.

If it is not a crisis and you can wait a week I will do a search and possibly find the spare evaporator fan I have somewhere. I may also have the pertinent poop on the condenser fan. We are heading out for a week otherwise I could get at it tomorrow, but I got too much I have to get done.