[wiredgeorge]

In a toy hauler, I suspect the A/C is so high that a non-ducted, manual control lower unit would be impossible to reach. If it goes to a bedroom, I suspect there won't be any wiring for the 2nd A/C to other than power but the thing may have connection to a dual zone thermostat as trailers are getting pretty sophisticated. The four wire thing is what connects Dometic Brisk to lower part I think.