Installing the Heater Control Board

These steps are generalized instructions.  Any changes you make to your car are your responsibility.  Be sure you understand the entire process and make sure you follow any safety precautions required.

The heater control board requires 12vdc power from the car as well it needs to be connected to the steering wheel's heater/temperature sensor.

One connection is easier than the other.

12vdc power connection (the hard one)

The Model 3/Y steering wheel has two connectors located behind the air bag.  The connector on the right is the air bag connector.  We don't do anything with that connector.  The connector on the left (with 3 wires) is the connector that provides power and communications between the car and steering wheel.

To gain access to the connectors the airbag needs to be removed.  There are a number of youtube videos that can help with this process.  Tesla also provides service documentation through their service site that you can reference.

The air bag is no joke.  Its a pyrotechnic (i.e. explosive).  Don't mess around.  Follow the instructions and be safe.

Once the airbag has been removed the steering wheel can be removed (to make it easier to work on).  Again there are a number of YouTube videos that can help with this process (Often you can find helpful videos by searching for yoke swap videos - they tend to show the removal of the steering wheel).  Also the Tesla service site can provide detailed service documentation to help with the process.

The left connector has 3 wires in it.

  

We are concerned with pins 1 and 2.

The pins/wires have the following details:
Orange/Black (Pin 1) = Ground
Yellow/Black (Pin 2) = 12vdc
Grey/Black (Pin 4) = LIN

The heater control board comes with a power pigtail.  This pigtail needs to be spliced into the Ground and 12Vdc wires.

<pic of power pigtail>

The red wire on the pigtail is + (or 12vdc) and the black wire is - (or ground).
The connections can be made in a number of ways (soldering, wire splice, etc), but be sure that the connection is secure and insulated.  At max draw the heater control board limits the current consumption to just under 4 amps,  Be sure that the method of splicing can handle this kind of current load.

Do not connect the wires backwards.  This will cause a fault in the car and the only way to clear the fault (after you fix your wiring) is to let the car go to sleep over night or to disconnect 12v power completely.

 

Heating Element and Temperature Sensor (the easy one)

The heating element and temperature sensor are connected via an OEM connector.  This is the light blue connector attached to the retrofit heater control board.  

To make this connection you need to disconnect the existing wiring from the OEM controller.  The connector is located in the bottom of the steering wheel under the trim piece.

You can wiggle the connector pair out and then remove the black male connector from the blue female connector.  Once removed the blue female connector can be clipped back in the original place.

The black connector can then be plugged into the blue connector on the retrofit heater control board. 

 

Physical Install

Once wiring has been completed the retrofit heater control board can be tucked behind the left scroll wheel.

Wiring can then be cleaned up and the wheel can be re-assembled.

You can see the new connection to the heating element and temperature sensor at the bottom of the above image.  You can also just see the original OEM connector just peaking out