Citroen C5 Tourer 2011

[JohnD]

I may have posted about the reversing radar before, but in case; it failed.   I discovered that the sensors, mounted across the rear bumper, tick!     It's very quiet, but as I have a stethoscope (of course) I could listen and pick out the one that didn't.      Bingo!    I ordered a new sensor online and fitted it - easy-peasy!    But still the system doesn't work!     I surrendered and took it to a local independant garage.  He smiled softly and informed me that Citroen use exactly the same sensors as I fitted, but they are tagged, and the system will accept nothing else but a Citroen tagged sensor.      In all honour, I had him order me un vrai capteur  and now, it works!   Twenty times the cost of Diy, but anyway.    Knowledge and expertise never come cheap.

But now, I have another annoying problem.   The cabin ventilation fan is on, ALL the time.    I wondered if it was the cold weather, but after a good run it was gettig toasty plus-plus in there, and the fan was still running.    I can turn it off only by turning off the aircon.   

I wonder if it's a cabin thermostat problem?     I have an OBD reader, but it's a cheapo, so any ideas where to look?  

Thanks, 

John