Can You Replace Just The Rooftop Unit Of An AC System With An Analog Thermostat

Updated 03/27/2023 | Published 03/24/2023

Question:

I have a 1995 Coachman Santara class A motorhome, It has a Dometic Duo-Therm roof mounted AC model 600315.421 the thermostats are analog, I need to find a replacement AC that will work with my existing wiring and thermostats.........HELP

asked by: Lexie

Expert Reply:

When you replace just the rooftop unit and keep the air distribution box, controller, and thermostat of your AC system the only thing you'll need to check us just the connector on the wire harness that hangs down from the rooftop unit and connects to the controller.

The thermostat is still going to communicate with the controller in the same way and the controller will be the one to tell the rooftop unit to kick on. If your unit has a heat pump then you would need to adjust the dip switches on the thermostat to heat strip instead of heat pump as you'll no longer have a heat pump once the unit is replaced as the units we carry only have an optional heat strip as a heating source.

The connector on the wire harness will either be a 6-pin or 9-pin (pictured below). If you have a 9-pin connector then you'll just need to pick up an adapter # ACCOLKIT to go along with the new unit. You can replace your old Dometic unit with the Advent Air RV Air Conditioner # ACM135 you were looking at or the # ACM150 if you'd like a higher BTU rated replacement for more efficient cooling.

expert reply by: Kevin C