Temperature Controller Wiring and Programming



For proper wire size for your heater, see wire chart here, or call 936 687 2267 and speak to a technician. To purchase  GXL wire click here.


  1. Run approx. 4” of 16ga (+) wire loop from contact #1 into contact #11 found on the TEMPERTURE CONTROLLER.
  2. Connect the 16ga (+) wire from the + side on the CONTACTOR to contact #2 on the TEMERTAURE CONTROLLER. (6’ coil included)
  3. Run 16ga wire to a + source of ignition/key switch or fuse panel into contact #11 on the TEMPERTURE CONTROLLER You will have (2) wire in contact #11. (This is used to switch the controller on/off when the vehicle is switched.)
  4. In STEPS (4 & 5) you will be using the proper gauge wire for your application. For proper wire size for your heater, see wire chart at www.dcthermal.com under installation help or call 936-687-2267. Connect adequate gauge wire from the battery to the + post on the CONTACTOR.
  5. Connect adequate gauge red wire from the heater to opposite post on the CONTACTOR.
  6. Connect 16ga (-) wire from heater to vehicle ground (SEE CHART)
  7. Connect 16ga black wire (-) from CONTACTOR to the battery ground. (6’ coil included)
  8. Run 16ga wire from the – side of the battery or chassis ground to contact #12 on the TEMPERTURE CONTROLLER (This wire is the ground for the temperature controller.)
  9. Connect the white temperature sensor leads to contacts #9 & #10 on the TEMPERTAURE CONTROLLER. DO NOT CUT WIRES!
  10. Set fan switch on the heater to the HIGH or LOW setting.


Programming the Temperature controller


We recommend that you read the both set of instructions to become familiar with the Temperature Controller.

When the controller is 1st powered on, you will see COOL icon and the current temperature are set in Fahrenheit.

In order to make the controller work with your heater, you will need to change minimum of (3) settings,E3, E4, & C2. To change these settings you must enter the program mode. This is done by holding down the SET button for 6 seconds. After 6 seconds, the E1 begins to flash, release the set button. Pressing the SET button again will scroll you through the different parameters from E1 to C2. Press the SETbutton until you get to the desired parameter. If no button is pushed for 10 seconds, you will return to the home screen where the current temp is displayed.


Set E3-OFFSET or HYSTERESIS as it is referred to in the factory instructions. HYSTERESIS is the difference in what the temperature sensor reads and when the controller will tell the heater to come on. We recommend a setting of at least 2.0. An example would be: if the display reads 70 and you have a hysteresis of 2, the heater will not come on until the sensor reaches 68 and will shut off @ 70. The factory default is set to 7.2 F and 4.0 C. While E3 is flashing, press the o to adjust to the desired offset. This keeps the heater from repeatedly cycling on and off. This can be set as desired by the operator.


Next you will need to set the E4 or DELAY. The factory default is 2 minutes. This is a time, which once the display reaches the set temperature; the controller will delay the heater switching on. We recommend a setting of 0 or NO DELAY. If a delay is desired, set the desired time here by using theoarrows while E4 is flashing. If the desired temperature is lower than the home screen display, theHEAT icon will appear and the heater will come on after the delay time has expired. If the HEAT icon flashes, the controller is in the delay mode. The timer will start at this point and once the desired time has expired, the heater will turn on.


Next you will need to set C2 to HEAT. After holding the SET button down and you are in the program mode press SET until you get to C2. Factory default is 0 for cold; you need to change it to 1 for heat by pressing  ARROW


This is all the programming needed in order to make your heater and temperature controller compatible. When you return to the home screen you can set the desired cabin temperature by pressing and releasing the SET button and using the o button to set the desired temperature.


If you would like the display to read in Celsius, hold down the SET button for 6 seconds and you are in the program mode, press SET until you get to C1 Factory default is 1 for F; you need to change it to 0for C by pressing the ARROW



This temperature controller is a 12-24 volt controller.


The contactor will make a small amount of noise when engaging, We recommend you place the contactor away from vehicle operator to ensure limited unwanted noise.