rubberjohnson
Member
Hi,
The interior heating is playing up. Started a month or two back when it decided when it was going to give hot or cold air, rather than on request. Now it just blows hot. When it started playing up I felt the HCV (replaced a year ago, used the proper Ford part as I've had problems with other ones before) and noticed that on full 'cold' setting I could sometimes still feel it 'thumping' (opening and closing), i.e. it wasn't recognising that it should be fully closed, but the HCV was working.
Now I can't feel it 'thumping' at all, on any setting. I tried a replacement heating control module with no success (subsequently tested original and replacement and the resistor seems fine, going from about 10k to zero).
I have put a meter across the terminals on the plug going into the HCV and I get zero at one, 14v (when the car is running) at the other, whatever setting I have on the heating dial.
I assume that the HCV should be getting either zero or 14v, for either closed or open, and it should jump between the two to make the solenoid work for different times depending on the heater setting?
All in all, this says to me that the wiring is working at the HCV(I get 14v) the heater controls are working (the resistor is functioning) but there's something stopping the on/off signal from the controls getting to the HCV. But this is partly guesswork, I don't know how the electrics function for the HCV.
Before I start pulling the dash apart trying to trace any problems, and try and dig out the correct wiring diagrams from the Ford Service CD, has anyone got any pointers? Things I could be trying to home in on the problem? Electrics aren't my strong point, so any and all tips gratefully accepted!
Cheers!
The interior heating is playing up. Started a month or two back when it decided when it was going to give hot or cold air, rather than on request. Now it just blows hot. When it started playing up I felt the HCV (replaced a year ago, used the proper Ford part as I've had problems with other ones before) and noticed that on full 'cold' setting I could sometimes still feel it 'thumping' (opening and closing), i.e. it wasn't recognising that it should be fully closed, but the HCV was working.
Now I can't feel it 'thumping' at all, on any setting. I tried a replacement heating control module with no success (subsequently tested original and replacement and the resistor seems fine, going from about 10k to zero).
I have put a meter across the terminals on the plug going into the HCV and I get zero at one, 14v (when the car is running) at the other, whatever setting I have on the heating dial.
I assume that the HCV should be getting either zero or 14v, for either closed or open, and it should jump between the two to make the solenoid work for different times depending on the heater setting?
All in all, this says to me that the wiring is working at the HCV(I get 14v) the heater controls are working (the resistor is functioning) but there's something stopping the on/off signal from the controls getting to the HCV. But this is partly guesswork, I don't know how the electrics function for the HCV.
Before I start pulling the dash apart trying to trace any problems, and try and dig out the correct wiring diagrams from the Ford Service CD, has anyone got any pointers? Things I could be trying to home in on the problem? Electrics aren't my strong point, so any and all tips gratefully accepted!
Cheers!
k:
