Hi, I have a D4 heater and controller in one part of my vehicle and blow the hot air into a second part of my vehicle and keep it at the temperature set on the controller, even though the area where the controller is installed will be cooler. If I install this sensor in the second part, will it control the temperature output from the heater? If so, which wires do I connect it to in my loom - wire colours?

Eberspacher heaters by default regulate heat output hence room temperature via referencing the temperature of the air being drawn into the heater room air inlet. So currently your heater is regulating heat output according temperature in the room area it is installed ( if it is installed using interior air recirculation, and not drawing air in from outside). Installing a temp sensor allows the heater to reference the temperature of the air at the sensor position rather than at the heater air inlet which in many circumstances is favourable. The sensor is connected to grey and brown/white cables from the heater harness (see quick diagram attached) typically but to be 100% on this we'd need to learn a little more from you regarding your heater build year, whiche controller, and which harness is installed. Perhaps send a photograph or two of your heater harness and heater dataplate to sales@butlertechnik.com