Heater Control Cable / Valve problem

[Dannn]

Hi

2005 Focus. I'm getting no hot air from the heater, just cold air. (I'm a newbie, so apologies in advance if I'm mis-posting.)

I've removed the stereo, and I can see that the mechanical heater cable isn't retracting when the temperature knob is turned to hot. I assume there should be some kind of spring mechanism at the other end of the cable which pulls the cable back to open a heater control valve.

So my first (very basic) question is: Where would I find the other end of this cable (where the spring mechanism is)? Is it easily accessible? I read somewhere that I should remove the lower panel in the driver's/passenger's foot-well, but I've done that and cant see anything that looks relevant.

And the next question: What are the likely causes? Kinked cable, broken cable, seized valve? How easy is it to replace a cable?

In case, I haven't explained clearly - I'm attaching a photo showing the end of the cable that I'm talking about. In the photo, it's disconnected from the temperature knob, and you should be able to see that it isn't retracting back into its sleeve.

Thanks in advance for any suggestions.

.

 

 

 

[JW1982]

The cable is not retracted by a spring loaded mechanism. The cable is simply connected to a flap inside the heater housing. The flap controls the air stream through or arround the heater core and this way controls the air temperature.

The cable is basically pushed and pulled by the temperature knob mechanism. On you picture the cable is bent. this is not correct. The end link of the cable needs to be straight otherwise it will not work correctly.

 

A bent temperature control cable can be caused by a blocked or seized flap inside the heater housing. During time the rubber seals arround the flaps can deteriorate and expand a little bit. This prevents the flaps from moving freely inside the heater housing. If this happens the complete heater housing needs to be replaced.

[FatHead1979]

3 hours ago, JW1982 said:

The cable is not retracted by a spring loaded mechanism. The cable is simply connected to a flap inside the heater housing. The flap controls the air stream through or arround the heater core and this way controls the air temperature.

The cable is basically pushed and pulled by the temperature knob mechanism. On you picture the cable is bent. this is not correct. The end link of the cable needs to be straight otherwise it will not work correctly.

 

A bent temperature control cable can be caused by a blocked or seized flap inside the heater housing. During time the rubber seals arround the flaps can deteriorate and expand a little bit. This prevents the flaps from moving freely inside the heater housing. If this happens the complete heater housing needs to be replaced.

And that means it's time to take the whole dashboard out, it's a huge job that I did recently to fit a new heater matrix.  Easy £500+ labour for a garage to do the job end to end as they'll likely charge at least 1.5 days labour, assuming they'll even contemplate the job at all.

[Dannn]

OK - Thanks for the feedback.

With the help of your description, I found that I could carefully push/pull the cable by hand to control the temp. But it's very stiff - too stiff for the knob to push without bending the cable. At least, I've managed to leave it set on 'warm' for the moment.

I was hoping there would be something that I could loosen up with a bit of WD40 or whatever, but it sounds like that's not an option.

Thanks again for the info.

 

[mrmetallica]

i had this on my mk2 fl .found out it was a wire catching on a cable after id bought a new cable .just make sure nothing is in th way of it.