Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Control System Inputs
The climate control assembly has 3 system control inputs:
Function Selector Switch - The function selector switch combines a vacuum selector valve that determines air distribution and an electrical switch to supply battery voltage to the A/C compressor circuit and the blower motor circuit. When the function selector switch is in the MAX A/C, A/C, A/C RECIRC (Hybrid), FLOOR/DEFROST or DEFROST positions, the A/C compressor will be operational. The function selector switch can be installed separately from the climate control head unit.
Temperature Control Switch - The temperature control switch setting determines the air temperature. Temperature selection is accomplished through a cable connected to the temperature blend door. Movement of the temperature control switch from COOL (blue) to WARM (red) causes a corresponding movement of the temperature blend door and determines the air discharge temperature that the air distribution system will maintain. The temperature control switch can be installed separately from the climate control head unit.
Blower Motor Switch - The blower motor switch controls the blower motor speed by adding or bypassing resistors in the blower motor switch resistor in all function selector switch positions except OFF. The blower motor switch can be installed separately from the climate control head unit.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.