How do the three AC units work?

[dedmiston]

Our Elevation toy hauler has three air conditioner units: One in the front sleeper, one in the main quarters, and a third one in the garage. The main AC and the front sleeper both work just fine, but we can't seem to get the third one to come on. I can't tell if there's something wrong with that AC or if it's somehow "managing" the three units in a way that I don't understand. I've tried shutting off the front AC and/or turning its thermostat all the way up so that it won't come on, thinking that the rear AC needs the front one off before it can come on, but no matter what I do I can't seem to force that one on.

I have the "problem" unit set to auto and I've turned the temp way down. Nothing seems to work so far.

I still feel like it's something I'm overlooking and not something defective, because I could have sworn it was running on a previous trip. It might have gone bad though. It's hard to say.

[Randy68]

Circuit breaker maybe or maybe separate plug on outside trailor for the garage.