Air Con: aircon - too hot too cold too hot too cold..

[vidapura]

['04 V40 1.9 Diesel 160k miles]


Folks,

My v40's aircon has only two settings.. too hot or too cold.

If I leave the temp selector on the 'blue' setting (at the bottom of the dial) and turn the fan on then its cool but eventually gets too cold.
If I set the temp to anything other than the bottom 'blue' temp then it just blows hot eventually..

So it can't maintain, say, 18C if I select it.

I don't have an obdII cable to get at fault codes etc.
So I'm probably pushing it asking this .. But..would it be possible for anyone to say whether they think this is just a regassing issue or is it a controller or something else?

Obviously I'm not giving a lot to go on... but if its able to blow cold I'm thinking the gas is ok?

Maybe someone could tell me if there is a way to get a display of the fault codes ? On my old passat the clima panel could be put in a mode that displayed fault codes...

Thanks for looking...

Vida

ps: this could also me being stupid about how to use it.
Does fan have to be set to Auto when I select a temp?

[xco]

Sorry dont know how to fix it but it sounds like a thermostat or temp sensor issue.
Some one in the know will be along shortly to advise you.

[bobthecabbage]

It does seem to work best if you set everything to auto and make sure the vents are open.

But in this case it sounds like its not detecting the temperature properly.

On blue you get full cooling and on red full heating regardless of temp.

There is a sensor behind the little grill in the control panel with a little plastic hose that draws air from the cabin over the sensor for an accurate reading.

There are a few threads on here about removing the climate control unit and replacing various bits.

Could be that your hose wasn't reconnected or the sensor is duff.

You'll be looking at the proper volvo diagnostic equipment if you want to interrogate the climate control unit I expect. Several members have working clones of the equipment and software and may be able to help out if you can get to one of them.

Hopefully someone useful will be along with the links shortly.

[gatos]

Even though I have never heard of this exact problem, it could be various thing that could cause this.

Remove the fascia of the heater control panel and clean the fluff on the temperature sensor. I doubt it will solve your problem, but it is a free fix and will only take you a couple of minutes to do.

Things that could be causing this, could be the actual heater control panel temperature rheostat it faulty, in which case you will need a replacement heater control panel. Or it could be that the motor opening and closing the flap is faulty, or one of the other temperature sensors is playing up. Ideally, you need to get your codes read with VIDA DICE.

You can check if the hot/cold air flap motor is working properly. It is the one behind the stereo. So if you remove the stereo (MAKE SURE YOU HAVE THE SECURITY CODE before you do this) you can see the motor arm at the bottom left. I just went out and did a video. I just need a way to post it here. I moved the temperature knob in increments of 2 degrees at a time and you can see the arm moving a bit at a time. Then towards the end of the video, I moved the knob from max to min and back and you can see the arm moving continuously from one end to the other

Interesting bit starts at around 39-40th second

https://www.dropbox.com/sc/3lyi7cfrf...vp6ovRq4yl80la

[stephend]

Related to what gatos said, on mine I found there was a flaky connection at the main multipin connector. If you squeezed it hard, then the hot/cold flap responded to the temperature control, but otherwise not. I used to find it was random whether it would blow hot or cold, and I guess what was happening would be that you'd momentarily get a connection, perhaps as the car went over a bump, and it would adjust to whatever the current setting was.

[vidapura]

Thanks folks for the detailed replies.
Really appreciate them.
Gatos that video is brill... I don't think I'll be able to get that far tho as the car came without any docs so don't have the radio code... sigh.

I'll see if I can find a thread that shows how to get at the sensor behind the grille.

Just one more thing.. I notice that with this car when I put the blower on full blast (regardless of temp) I don't get an air current up into my face like I would in my old passat... no matter what vent setting I pick...

Is that the way it should be or should you get a draft off of it like in other cars?

Or have I got some sort of vent control problem?

[coffeejunky]

Originally Posted by vidapura

Thanks folks for the detailed replies.
Really appreciate them.
Gatos that video is brill... I don't think I'll be able to get that far tho as the car came without any docs so don't have the radio code... sigh.

I'll see if I can find a thread that shows how to get at the sensor behind the grille.

Just one more thing.. I notice that with this car when I put the blower on full blast (regardless of temp) I don't get an air current up into my face like I would in my old passat... no matter what vent setting I pick...

Is that the way it should be or should you get a draft off of it like in other cars?

Or have I got some sort of vent control problem?

You can phone your local Volvo dealer or Rufe at FRF Volvo, they usually give codes for radio free. Don't pay for it, though Just keep trying dealers till you get a compliant one.

[druid]

Pull your radio out (without unplugging it) and you MIGHT find the code written on it. Might. its what i did with mine.

[vidapura]

Cool,
I'll try that tonight (if its stopped raining) and see if I'm lucky.
Whats it look like ? A four digit numeric code or something?

Thanks

[coffeejunky]

Originally Posted by vidapura

Cool,
I'll try that tonight (if its stopped raining) and see if I'm lucky.
Whats it look like ? A four digit numeric code or something?

Thanks

Correct!