The HVAC temperature will not switch from hot to cold and back why?

Good to hear, Steve W. Is one of our best. Please use 2CarPros anytime we are here to help.

Cheers, Ken

Air temperature actuator is on the bottom of the heater case. This is a picture of manual system, auto temp is similar.

Hi and thanks for using 2CarPros.

Either you got a bad actuator or you switched the polarity position on the plug (forced the plug together opposite to how it should go.) The directions of power to the motor determines what direction it will move. If it is plugged in backwards, this is what will happen. Recheck to make sure that isn't what happened.

Let me know what you find.

Joe

I attached some additional pictures and a flow chart for you.

Check the voltages at the connector for the blend door. I identified the power and ground for the motor.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Roy

It sounds like there is an issue with the temperature blend door and/or blend door cable or actuator. This particular model vehicle used two different types of control systems depending on whether or not it was equipped with air conditioning. Attached below are two different diagrams of these systems. The first is the heat only version which uses cables to control the blend/mode doors. The second is the system with A/C which uses electronic actuators for these doors.

If you have heat only, have someone move the temperature control while watching the cable/lever at the lower left area of the heater housing. Based on you description, it sounds like the cable may be loose where it attaches to the door lever.

If you have A/C, remove the glove box assembly to access the door actuators. Looking at the second diagram below, you can see that the blend door/temperature actuator is at the top, toward the center of the housing. Again with someone moving the temperature control, observe the actuator and make sure the linkage is all in place and not loose or broken.

Let us know what you find!

Welcome to 2CarPros.

The blend air door actuator is under the dash on the HVAC unit. Here is a link that explains in general how one is replaced:

https://www.2carpros.com/articles/replace-blend-door-motor

Here are the directions specific to your vehicle. I attached two pics. One shows the HVAC unit under the dash, and the other, I circled the actuator in question.

REMOVE OR DISCONNECT
1. Battery ground cable.
2. Instrument panel compartment for excess.
3. Electrical connection.
4. Screws.
5. Actuator.

ADJUST
1. Install the battery ground cable.
2. Electrical connection to the actuator.
3. Turn the ignition key to the accessory position.
4. Allow the actuator to position itself.
5. Turn off the ignition key.
6. Disconnect the electrical connection from the actuator.
7. Disconnect the battery ground cable.

INSTALL OR CONNECT
1. Actuator to the heater assembly.
2. Screws.
3. Electrical connection to the actuator.
4. Instrument panel compartment.
5. Battery ground cable.

Let me know if this helps or if you have other questions.

Take care,
Joe