You can add a T-stat to control your A/C unit. In addition to using a T-stat for controlling the A/C, I also wired my propane furnace
and the heat strips located in the A/C to it as well. With a flip of a toggle switch next to the T-stat, I go from either cooling (A/C) or to heating (with either the A/C heat strips or the furnace
, or both heating units simultaneously.) For controlling the AC power to the air conditioner you will need a 12 VDC Relay to hook up to the T-stat, rated for 120 VAC at 30 Amps to power up the A/C unit on the alternating current side. If you don't have, or don't want to hook up the furnace as well, then just delete the part of my drawing that goes to the furnace, and just use the A/C part of the schematic.
As an aside, to combat the loud noise of the A/C coming on, (compressor start-up noise,) I removed the Dometic Hard-Start capacitor inside the roof unit of my Polar Cub A/C, and replaced it with the Micro-Air Easy Start that I mounted in the space aft of the capacitor enclosure. Yes, it's not cheap, but IMHO it was worth every penny.
Before the Micro-Air Easy Start the whole trailer used to shudder and shake when the A/C came on. It was enough to wake the dead. Now, you only hear a nice quiet gentle whoosh of air, no more rumbling like a freight train.