Bay Breeze A/C Question

I have the original Bay Breeze A/C in my 1965 Overlander which works great with one exception. It has be oiled and services recently but I am having an issue with the fan suddenly stopping. It runs great, cools fast and the compressor kicks on and off fine. The fan will mysteriously shut down and refuse to kick back in when the compressor signs on after it has been running for a good bit if time. I have to shut it all down, wait about an hour and then the fan is fine. Does anyone have a clue as to what cold be causing this? Thanks, Dom