Heater not working properly

Hi,

It sounds like there is an issue with the mode door or mode door actuator. However, this actuator is controlled via an electronic signal and shouldn't change when applying the throttle. That leads me to feel the two (door and actuator) are no longer connected.

I need a little more info. Is the system an automatic or manual climate control unit? Does it have rear heat and A/C? Also, I will need to know a specific number. It's called an RPO number (D07). That number indicates if you have a center console or not. See pic 3.

If you look at pics 1 and 2, they show the location of the mode door actuator for both the automatic system and manual (A or M). Check to see if it is there and tight.

Let me know.

Joe

Sounds good. However, if it has a factory center console, it will have the number. If not, then it will not have the number, so don't go crazy looking for it.

Let me know.

Joe

Hi,

I went through the specifics on your vehicle's issues. It could be a mode door problem, but to replace it will require the removal of part of the dashboard, the HVAC control unit under the dash, evacuation of the AC Freon, and coolant. I can't believe how much needs to be taken apart to access it. If it was something easy to access, I would recommend starting with it, but that isn't the case.

So, we are going to try to look at this from a different angle. Since the issue happens whenever it feels like it, we should start simple. You mentioned the fan will blow high or low even with the unit off (through the defroster). Let's check a few possible possibilities in the electrical system. It could be a loose or damaged connector or related to the blower motor control module.

I attached the wiring schematic below and highlighted different possibilities. What I need you to do is check to confirm the control module processor is tight as well as the connector at the blower motor itself. The remaining pics simply show the locations of these components.

Also, after further research, I found a few technical service bulletins related to the motor running after everything is off. According to the TSB, the blower motor control module processor is bad.

Here is a link you may find helpful when checking the wiring:

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

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below.

One last question. Does it have automatic climate control?

Hi,

I'm glad to hear the problem was found. Interestingly, the resister doesn't control the airflow direction, but rather it is for fan speed.

I do appreciate the update. Please feel free to come back anytime in the future.

Take care,

Joe

The airflow direction is controlled by what is called a mode door/actuator. That was my primary focus when you indicated it would come out the defroster regardless of selection. I was thinking you had it set in a different airflow direction and it would come out the defroster on and off. Sorry about that.

I attached a pic below showing its location.

Let me know if there is anything I can do to help.

Take care,

Joe

You are very welcome. Please let me know if there is anything I can do to help.

Take care,

Joe