Buzzing noise and blowing hot air

[s567]

I have a 2010 Fiesta Titanium with a problem with the climate control.

Intermittently whilst driving there is a loud buzzing/crackling noise from under the dashboard (possibly the left hand side) and then for the rest of the journey all the air blowers will only kick out very hot air. 

The air is hot even with the AC on and the climate control set to well below the outside air temperature.

Any ideas what could be causing this?

[unofix]

The plastic cam for the air director in the climate/heating unit has broken.

Generally a dashboard out and heater removal required to get to the part.

[s567]

On 8/20/2023 at 11:11 PM, unofix said:

The plastic cam for the air director in the climate/heating unit has broken.

Generally a dashboard out and heater removal required to get to the part.

Thanks, is there any diagrams showing this? Just struggling to understand why it would work intermittently.

[unofix]

This thread may help you:

 

[s567]

I have checked all the actuators and they work correctly, which makes sense as at the start of the journey the air is cold and then it suddenly changes to hot air so the actuators must be moving to be able to do this.

I have also given the cabin air temperature sensor a clean with no improvement.

I have found the only way to get cold air is to set the temperature to LO and then the blowers will blow cold air. If you have the temperature set to 16C and it is 22C outside the blowers kick out hot air from the engine (much hotter than outside air).

Could it be a control module or something?