Can I Power a Furrion Chill Cube Thermostat From Coach 12V Power?

Updated 09/08/2026 | Published 08/27/2026

Question:

I wired the thermostat to the Box/controller that came with the thermostat located in the Chill Cube and the furnace wires to the thermostat as indicated in the manual. It works as intended with the AC as well as the furnace with one exception... It appears that the thermostat is powered by the AC. So, if not connected to shore power, the thermostat is dark/non-functional which prevents the furnace from operating. That said, can I connect the 12V/Ground leads from the thermostat to the old 12V/Ground feed located at the AC instead of the 12V/Grd from the Thermostat control box at the AC? If so, do I need to bridge/join the Grounds from the control box and coach together?

asked by: Paul D

Expert Reply:

Hey Paul, thanks for reaching out. Yes, you can power the Furrion Chill Cube thermostat # LC74DX from the coach’s constant 12V supply instead of relying on the 12V feed coming from the Chill Cube control box. The thermostat is a 12V device and needs constant battery power so the furnace can still operate when you are not connected to shore power. The fact that yours goes completely dark when shore power is disconnected tells me that the thermostat is losing its 12V supply along with the AC.

I recommend using the old constant 12V positive and ground at the AC to power the thermostat. Yes, tie the coach ground and control-box ground together so everything shares the same ground reference. Leave the communication wires between the thermostat and Chill Cube control box connected as they are now. Before making the change, just verify with a multimeter that the old 12V feed stays hot with shore power disconnected. Once that checks out, this setup will let the thermostat and furnace operate from the RV battery even when the Chill Cube has no 120V power.

What rig are you installing all this in?

expert reply by: Jesse M

Thermostat for Furrion Chill Cube Ducted RV Air Conditioners - Single Zone
(click to enlarge)

Paul M.

9/8/2026

Jesse, Thanks for the information - will definitely give it a try. As a follow up - I have noticed that the thermostat is reading the ambient temperature about 6-8 Degrees below the actual temperature (this was confirmed with two other thermometers placed within a foot of the Thermostat). I assume this is a Customer support call to Furrion/Lippert. Thanks, Paul

Jesse M.

9/8/2026

@PaulM Yes, I agree. A 6-8 degree difference is more than I’d expect, especially since you verified it with two separate thermometers right next to the thermostat. That inaccurate reading can definitely affect how the Chill Cube cycles and maintains the temperature you actually want. I’d definitely recommend you contact Furrion/Lippert technical support on this one.