2004 XC70 air con sensor problem

[lakey]

I have recently purchased a 2004 xc70 that has been diagnosed as having a faulty air con sensor. Apparently this resides behind the little 3 bar grille on the air con controls panel. Unfortunately, I have been told you have to purchase the whole panel with all the controls on (part no. 8691876), not just take the panel off and replace the sensor! I have been quoted a price of £450 from Volvo just for the parts. I was wondering whether any of you out there may know of a cheaper alternative source for this part (I live on the Hants, Surrey, W.Sussex border).

The problem I have is one of temperature. If you set the controls to 24 degrees it blows warm as as it should, but over a period of minutes gets colder and colder and you have to keep turning the dials up to get any heat at all. In the end you are on the red maximum setting and that sets all the fans going blasting out masses of heat. Anybody had this problem before ?

Many thanks for any help you can give me.

Chris.

[60041]

Have you tried cleaning it? If you look into the grille, it is more than likely you will see it clogged with fluff and dust. I cleaned mine by carefully picking all the rubbish out with a small piece of bent fuse wire and it was amazing how much I got out. My symptoms were not as bad as yours, but the temeprature would fluctuate in the car and it would need constant adjustment. After cleaning everything was back to normal.

[BobS]

Hi Chris,

As 60041 has said fluff builds up and causes strange problems. Try hoovering through the grill. But if the thermistor is broken or damaged see this thread
http://www.volvoforums.org.uk/showthread.php?t=99108&highlight=thermistor

Post 7 onwards.
This give the part number from RS components.

Worth a read?

Hope it helps,
Bob

[lakey]

Many thanks for your replies BobS and 60041. My local Volvo specialist (RT Mechanics, I highly recommend them) have carried out all the work on my car and they have tried hoovering out the grille.

I have ordered a new part from RS. Many thanks lads!

Chris.

[Jim314]

With a non-functioning thermistor, if the automatic button is off (LED not lit), will the HVAC work like a manual one?

My 2004 V70 has the basic manual HVAC, and I don't see much need for the automatic control. My wife's 2007 XC90 3.2 FWD (US base model) has the automatic HVAC with the dual thermostat knobs (but without the optional pollution sensing system), but I don't see any real difference in performance. Just something more to have to understand the details of correct operation and something to break and need an expensive repair.

On her XC90 the thermistor is visible in between the little slats of the grille, and, because of its light grey colour, one's eye is drawn to it . Before I knew what it was I thought it was some fragment of trash and considered prying it out. When I looked closely I recognized it as a sensor and left it alone. Is the thermistor supposed to be visible or is it supposed to be back a few mm or a centimeter so that it is not visible? I'm going to leave it alone even though I have an urge to push it further back so it cannot be seen.

Addn in editing

I just tried my wife's XC90 and with no LED lit in the 'automatic' the settings of the thermostat knobs do affect the temp of the air coming from the dash vents. This still doesn't answer the question of the possible manual operation of the HVAC if the thermistor is broken.

It will really be a service to Volvo owners who care about not needlessly throwing potfulls of money at their car to discover that the broken thermistors can be inexpensively replaced.

[lakey]

I will let you all know soon. My replacement thermistor arrived today. Just got to book the car in now. Watch this space.

Chris.

[lakey]

Well, it is done......................and it works!!

Instead of £450 worth of parts and God knows how much labour, it was a £3.99 part and less than an hour!

Chris.

[Jim314]

Well, it is done......................and it works!!

Instead of £450 worth of parts and God knows how much labour, it was a £3.99 part and less than an hour!

Chris.

Very sweet . . . and very annoying that Volvo doesn't provide or support such a repair.

[Chris_Rogers]

Very good to know that the RS part works.

It was a bit of a guess on my part (given the specs from the thread) that this was the correct part.

[chiptivo]

I was the one on the other thread, who pulled and damaged the thing with tweezers when trying to clean it... :(

I ended up getting a second hand ECC and swapping the sensor between the units (As they are hard codded to the car).

I keep meaning to order the sensor and re fit to the ECC I brought on ebay and sell it back on ebay.. And make a profit.. :thumbs_up:

Thanks again, this brought back painful memories of my mistake..