climit control problem

mark21td · Post by **mark21td** » 04 Nov 2009, 09:22

I have a problem with my CC,
If I have the fan in auto and the temp setting in HOT the fan only blows slowly but I do get heat from it,
if I lower the temp a bit it blows cold air and the fan speeds up
the blower works fine in manual but still not that hot.
is this down to the litle fan in the dash (the one above the radio) as I beleave this is the temp sensor.

Sorry should of said it's a 97 Xantia vsx 1.9td.

jgra1 · Post by **jgra1** » 04 Nov 2009, 10:27

my post not relevant

mark21td · Post by **mark21td** » 04 Nov 2009, 10:32

Ah, I see what you mean, the only problem is if I use it in auto as you should it just blows cold !

jgra1 · Post by **jgra1** » 04 Nov 2009, 10:34

sorry Mark I wrote all that and re read yours twice and realised I had missed some important bits (late night)

I think if you are only getting any heat when fan speed is low, that maybe you just dont have enough coolant in the matrix, or there is something wrong with the air diverting flap that sends air to or away from the matrix..

the internal sensor shouldnt really affect the temp when you are on manual override.. that should give hot at any fan speed?

mark21td · Post by **mark21td** » 04 Nov 2009, 10:48

I know what you mean bout a late night, I've been on nights

I do get heat when the fan is in manual and heat setting is high just not in auto.

jgra1 · Post by **jgra1** » 04 Nov 2009, 12:22

ahh

in that case I think you may be right with your original prognosis... the sensor is easy to remove.. a small unit with a fan on.. I think they get pretty dusty.. may be worth removing it and having a look, make sure the small fan turns when the ignition is on and Auto selected?

I may test mine this week with a thermometer in the car..always wondered how accurate CC is

HDI · Post by **HDI** » 04 Nov 2009, 12:26

Ah , so thats whats behind those little slots !! If my pollen filters anything to go by I bet mine is caked in dust !! The CC in mine works but has a tendency to leave the upper air too cold after heating the cabin upto temperature in cold weather.

jgra1 · Post by **jgra1** » 04 Nov 2009, 12:29

I know in the 406, I am not happy in the car unless the climate says 23

which seems a bit high really..

will report back with thermometer readings.. I ahve a double sensor, one can go on vents and the other somewhere else..

HDI · Post by **HDI** » 04 Nov 2009, 12:34

Cool !! 8)

Clogzz · Post by **Clogzz** » 04 Nov 2009, 12:49

It’s deliberate for the fan to go slowly at maximum temperature setting.
The air is hotter when it passes through the heater core slowly.
Since it’s hot at maximum, it means that the motorised heater flap works.
The heat comes out mostly from the bottom, because it’s meant to rise.
The face and windscreen airflow is controlled by two cables on the top left slider.

Post by **CitroJim** » 04 Nov 2009, 21:37

Mark, if you do find the little fan in the cabin temperature sensor is good, clean and spinning nicely then your next best course of action is a good old Lexia session on it as the Lexia can exercise the temperature flap to ensure it's working well and check the operation of the three other temperature sensors. there's one in the air intake above the recirculation flap (impossible to get at), one for the footwell temperature and one in the middle of the heater box. If any are playing up they will confuse the climate control ECU.

The cabin air temperature sensor is a mite bit hard to get to if you need to replace it. Steering wheel off, cowls off, switch panel out and then wireless, ashtray, fascia vents and finally you can get to it

That's for a MK1. for a MK2 it's marginally easier as there is no need to remove the steering wheel...

HDI · Post by **HDI** » 04 Nov 2009, 22:16

Witches sister !! Is Anything on these things easy to do ??!!

Wonder when I'll get a chance to try a fabled Lexia ??!!

Post by **RichardW** » 05 Nov 2009, 12:09

You can, just, do it without taking the steering wheel off, but it's not necessarily easy.... Some of them seem to just pop out with a gentle wiggle, but the ones I have played with have been tight. Remove the radio and surround then you can reach in and try and push the sensor out - the clips are top and bottom, so it may just wiggle out. If not try taking the clock out so you can get to the side of the sensor.

On a MK2 you will need to remove the switch panel, as there is no separate grille for the sensor like there is on a MK1.

You may well find though, that the motor is broken - they use a small brushless DC jobbie, and the electronics are prone to going belly up, so the fan only kicks, not rotates.

MikeT · Post by **MikeT** » 05 Nov 2009, 12:47

RichardW wrote: Remove the radio and surround then you can reach in and try and push the sensor out - the clips are top and bottom, so it may just wiggle out.

That's the method I use and it works every time.

Jim, I think I've got a working spare for you - I just have to be sure my apprentice didn't damage it on removal

Post by **CitroJim** » 05 Nov 2009, 13:13

MikeT wrote: Jim, I think I've got a working spare for you - I just have to be sure my apprentice didn't damage it on removal

Thanks Mike

Will swap it for a Lucas DPC