Help! Sporadic temperature glitch - duct problem?
Posted: Sun Nov 25, 2007 9:14 pm
A fault has occured once for a short period a couple of days ago and today (Sunday) for over an hour though eventually seemed to sort itself. It did not occur at all on a 450-mile round trip on Tuesday or before that or between the above two events.
When it goes wrong, cold air is being blown into the car. With everything set to Auto, if I increase the temperature setting from say 21 to 24 then the fan speed increases as you'd expect as it tries to hit the new target temperature - but the air being blown in is cold. If I turn the setting down then the fan speed drops, so the "intelligent" aspect of the whole set-up seems to be working. This leads me to believe that the temperature detector inside the car is working correctly and the system's brain is thinking straight...
It must be that it is drawing in different temperature air from what it thinks it is. My guess is that a duct is disconnected at one end or loose somewhere. If it was split open or completely detached then it would not have occasionally worked eg. for the last 15 minutes of my last 45 minute journey.
Does this sound like a decent starting point for investigation? If so, how easy is it to get to the ducts to check them?
Thanks in advance for any help. I can see I need to get myself a workshop manual...
Nigel
When it goes wrong, cold air is being blown into the car. With everything set to Auto, if I increase the temperature setting from say 21 to 24 then the fan speed increases as you'd expect as it tries to hit the new target temperature - but the air being blown in is cold. If I turn the setting down then the fan speed drops, so the "intelligent" aspect of the whole set-up seems to be working. This leads me to believe that the temperature detector inside the car is working correctly and the system's brain is thinking straight...
It must be that it is drawing in different temperature air from what it thinks it is. My guess is that a duct is disconnected at one end or loose somewhere. If it was split open or completely detached then it would not have occasionally worked eg. for the last 15 minutes of my last 45 minute journey.
Does this sound like a decent starting point for investigation? If so, how easy is it to get to the ducts to check them?
Thanks in advance for any help. I can see I need to get myself a workshop manual...
Nigel