There have been other threads started regarding this issue on other coaches. You can use the search function to find and read thru them. I believe that the dip switches are located in the rooftop units. The literature you have from the replacement units should be helpful in locating the switches and in setting the appropriate ones. If the wiring of the new units was done correctly and included the appropriate furnace circuits from the coach, then the proper configuration of the dip switches should allow you to select and control the furnace at the the thermostats.