Heater/AC problem

[pvandal]

Hello, I have a fiesta 2014. I have a problem with heating/ac system. It always push warm or hot air , even set at LO. The actuator is operating (The 2 other actuators (defrost/vent/foot & In/out intake) works). The temp sensor works.

 

[Handy Andy]

There are many ways A/C could go wrong.

Best to check with a Shop that does AC, the fails in the chain of parts you'll need to make AC work range from the Front Condensers to the inner evaporator onto the hoses, fittings and various other what-nots that are needed.

To tell you where to start, is simply to verify the fuses are good, the Radiator Fan works and the AC pump kicks in when you turn it on - and runs, - then you know the electrical is ok.

But if there is no pressure of Freon left in the system, the AC compressor won't kick in.

So if the Tell-Tale AC light can't even work, the system has lost pressure and has a leak or failed hose.

 

[pvandal]

I had already went to make checked the AC, they told me everything is ok. they said the problem should come from the airmix trap (door). The actuator works. I ask to myself if the door trap may be broken?

 

[Handy Andy]

Trap Door?

Hmmm...

Some further disassembly is required...

The Trap door, you mean, the Blending door - if that door is broken the vane just sits there - mostly for Inside cabin air and the outdoor fresh air (Recirculated).

Another door is the one that lets the heater core and evaporator work together - Inlet door, that should be on the passenger side behind some trim that goes along the console on the passenger side, that panel pries off and goes from the front of the floor mat, back to and behind the shifter.

There are two "actuators" in that area, one on the case is the Blend door, the other towards the Body Control Module and Glove box is the Fresh recirculated actuator.

Then another is on the Drivers side - under the knee panel - just above the Accelerator pedal - it moves the drum that pushed air out those different floor, console and defroster - vents.

The "Blend door" works with the AC sensor by it - towards the front of the car.

There may also be a "Auxullary heater" that equipped in some models - you'll have to "run your VIN" to see if the option is installed on your Fiesta - if it is, that may be what this problem is.

There are fuses in the passenger (side) behind the Glove Box - this may be where the Auxilary heater fuse also resides - so you may need to check to make sure your AC system works but you may have to verify the Auxilary heater is not countermanding your AC unit - might have to locate that fuse and pull it to verify if AC works, then the controller for that AC system, is bad.

To help identify some of those "motors" heres a graphic showing COLOR CODE of the wires to these actuators.

You may be able to locate the correct one by identifying the wire color code at the connector to it.


Here's another graphic, showing the auxiliary heater wiring color code and the relay for it is in - behind the Glove box.

 

[Handy Andy]

Once you can find and identify the correct motor - if the actuator is bad, it won't move, but if it's simply ajar - the pin from the pivot on the output shaft - is not matching the "tab" the door is attached to, just unscrew the motor pull it out - start the car and move the heater controls to see if the motor is jammed or working - then once verified, the motor output pin and the tang/tab the door works with - just need to be aligned and then the actuator is reinserted and screwed down.

 

[pvandal]

Thanks for all info. I will check.

 

[pvandal]

For now, I had already change the actuator driver side, which one was making noise.(but I was knowing it was not the problem).
I checked the in/out and saw it was working.
The third one I demounted it and checked manually if working. And seems ok.
I will check for the Aux Heater you talk about.

Thanks

 

[Handy Andy]

While you see these working, is the vents Air temperature changing?

Then if its not, you can have Freon Pressure Ok, and even the Compressor...

But the problem you may have is the Constriction that forces the compressed (Compressor side) of the FREON to expand in the passenger compartment. It's called the Expansion Valve.

Expansion Valve - Ford (AV1Z-19849-C)
It would contain the restrictor - for the Evaporator side (Cooling side) to work.

Part number 15​

IF the Freon doesn't expand, the FREON can't cool, just blows hot.

So if the vanes in the motors to make the air vents blow air and work their Magic are ok, the orifice that makes the Freon cool from the compressor side, is bad, dislodged or damaged.