Big shout out to Old Biscuit
I had a dometic heat pump roof air unit in the bedroom that would run great for a few hours, then just shut down and wouldn’t restart. I could hear the fan motor hum like it was trying to restart but it wouldn’t. The front unit continued to work fine. My first thought was to replace the start/run capacitor. Worked for a while. Thought I had it fixed. Then the same thing would happen. After reading several other posts on here Old Biscuit would point to a bad communication cable that could possibly be the cause of these types of symptoms. I had a hard time convincing myself that this was the case, but it was the cheapest option rather than replacing the control board or thermostat. I pulled a new cable through the duct work and it works like a charm now. Just in time for summer.
Thanks Old Biscuit for your continued share of knowledge and insight.