V50 AC Blowing Warm - Temperature Sensor Blocked
 

I recently resolved an issue with the external temperature sensor on my '04 V50 by cleaning the electrical connectors in the door connector (as described elsewhere in these forums) but the AC still isn't blowing cold.

Before I take it to a local garage to get it re-gassed I decided to check for fault codes and it came up with:

"Blower Fan motor passenger compartment temperature sensor, Blocked"

I have had a search through these forums and other forums and I have found enough to make me want to get this checked before I have it re-gassed. So far I have not been able to find any guidance specific to the S40/V50 and I would be grateful for any guidance anybody can give me in locating and unblocking the sensor.

There is a temperature sensor for the AC in the passenger footwell. It's quite high up in the centre console and can be located by the wires running to it. Peeling back the carpet should reveal it.

Temperature sensor replaced. Error message went away but no change with the AC. The bought a bottle of refrigerant from Halfords which was a waste of £50 as it only took about 10% of the bottle before it said it was full. Then took it to a specialist my local garage recommended (Aircon Direct, Gravesend) who properly tested and regassed the system.

Still have a fault where the AC won't work if the outside temperature sensor malfunctions which it has started doing again so I have ordered a new sensor.

How is the outside temp sensor relevant for AC operational? I mean, yes - for auto climate calculations, of course, but if you put AC to LOW mode, it should blow cold regardless of temperature, no? I thought its like "override" button.
(I may be wrong, just thinking out loud...)

Exert from my little climate control data pages 'teased' from the internet years ago:

"the outside temperature sensor, (an NTC resistor), is located in the left-hand door mirror. The OEM transmits the signal over the CAN where it is captured by the CCM.

The CCM uses the signal to allow activation of the compressor down to a temperature of approx -5deg C.

The ECC also uses the signal to regulate the direction of the air in the passenger compartment (defroster, ventilation or floor or combinations of these).

Diagnostic trouble codes for the outside temp sensor are managed by the OEM"

So, if the system thinks it is less than -5deg C outside it may well prevent the compressor running.

You are 100% correct, I just wasn't very clear. :confused_smile:

The auto climate operation is now working when the outside temp sensor works, when the sensor sporadically fails the calulations go down the toilet. Before I took it to be serviced it didn't work even when set to LO.

The temp sensor, is it the one circled in the pic?

Looks like I have managed to get very confused and replaced the wrong sensor. The error going away seems to have just been lucky because it's back. :-(

So anyway...

* The AC system has been regassed so it now blows cold
* The clutch on the compressor has been adjusted so it doesn't cut out after ten minutes when it is warm
* The passenger compartment sensor has been replaced (didn't need to do that, damn!)
* The external temperature sensor (in the door mirror) has been replaced so it is now giving consistent readings but it was a non original item from eBay and is about 2 degrees too low but that's okay because at least the auto climate operation now works (I may get a genuine Volvo item in the future)

I think that Resonance may have helped me a load with that photo (thanks!) to help me identify the correct blower fan temperature sensor as accurately pointed out by Jarndyce but misunderstood by me (sorry).

Like it says under my name, I can be clueless at times and miss things first time round.

Any idea how they adjusted the clutch? My local AC place doesn't think it's adjustable.

because they either dont want to do it or want you to spend extra money...
recently had this done to my car - cost me 26e for the tool to remove clutch plate, thats all, works like a charm.

look around for AC Compressor Shimming keywords

https://www.volvoforums.org.uk/showt...=282543&page=2

also random vid on YT
https://www.youtube.com/watch?v=zOjq...ature=youtu.be