No hot air inside. Suspected 'air deflating flap' not working

[jms024]

Hello everyone! Happy new year first of all.

 

I am new here and would like to seek some advice from you guys.

 

I own a 1999 1.3 Petrol Skoda Felicia and have a problem in getting hot air from the blower fan. The blower motor spins and air comes out of the vents but on cold air flows in even when the knob is set to 'hot'. I have already replaced the coolant and I can confirm that the hoses going in and out of the heater matrix do get hot when the engine is running. I am suspecting that the flap which deflects the air is not working.

 

Do you have any suggestions of what should I check? 

 

Many thanks in advance.

Edited 10 January, 2015 by jms024

[RicardoM]

There is a steel cable that goes from the hot/cold knob to a dual flap. Most probably there is a problem at the end of that cable. That cable ends with a hook that moves a plastic lever which in turn moves the flaps. On one side of the heater/blower housing you'll see two black sleeved cables. One is hooked more towards the engine (that opens/closes completelly the air intake when you turn the blower speed knob from 0 to 1). The other one is hooked more towards the firewall. That one is what you're looking for. After you located it, check if the steel hook is engaging the lever and also if the metallic clip that holds its sleeve in place is firmly attached. In my car that clip was heavily corroded and eventually broke. It was a pita to find a replacement. Anyways, put a friend to switch the knob from hot to cold and you observe the cable steel core movement. See photo (my car is LHD).

Edited 10 January, 2015 by RicardoM

[jms024]

There is a steel cable that goes from the hot/cold knob to a dual flap. Most probably there is a problem at the end of that cable. That cable ends with a hook that moves a plastic lever which in turn moves the flaps. On one side of the heater/blower housing you'll see two black sleeved cables. One is hooked more towards the engine (that opens/closes completelly the air intake when you turn the blower speed knob from 0 to 1). The other one is hooked more towards the firewall. That one is what you're looking for. After you located it, check if the steel hook is engaging the lever and also if the metallic clip that holds its sleeve in place is firmly attached. In my car that clip was heavily corroded and eventually broke. It was a pita to find a replacement. Anyways, put a friend to switch the knob from hot to cold and you observe the cable steel core movement. See photo (my car is LHD).

280635917.jpg

Many thanks RicardoM! I will have a look at this. I have noted that when I flip the lever you mentioned, hot air began flowing in so what I need to check is why the flap is not following the knob of the control panel even though the steel hook looks still attached. I think I will have to take out the whole heater unit to have a clearer look at what is happening. 

 

Thank you very much again for your feedback

[RicardoM]

Thank you very much again for your feedback

You're welcome.

Keep in mind that is not enough to have the steel cable hooked to that lever. If the sleeve of the steel cable is no more attached to blower housing by that springy steel clip (see photo) the lever will not be actuated.

[jms024]

So finally I've had some spare time to tackle this issue. I found out that a piece of white plastic normally connected to the back of the 'hot/cold' selector knob which connects the knob to the cable which moves the flap was snapped out of its place.