I had a similar problem with one of mine and it turned out to be a thermistor. After running fine most of the day , lt would start acting up. the fan would keep running and the compressor would shut off. The fan would keep running and then shut off for a few seconds and then start again and the compressor would then come back on. After reaching temp then the comp. would shut off and the fan would keep running.
The HP worked just fine during the night .
Doug & Melba and sidekick Sugar
2014 GMC dmax, crew, dually
2015 DRV Tradition