Aircon not working - 2.0D

[Ducatimatrix]

Yet again the same question... I can see a lot of questions in this relation, but I am unable to find one that matches my situation

Basically I need to know where to start trouble shooting. Fluid is on, no leakage found and the pressure is good. I cannot hear the compressor turning on (idle stays the same, I cannot hear any difference), so no cold air is coming.

No fault with VIDA.

How to I determine if it is a relay, fuse or the actual compressor?
Can I test the compressor clutch?
I do not believe it is a electronic function telling the compressor "not to go on" since no fault is found with VIDA.

Note: 2008, V50, approx 120,000 miles

[LizardOfBodom]

Originally Posted by Ducatimatrix

Yet again the same question... I can see a lot of questions in this relation, but I am unable to find one that matches my situation

Basically I need to know where to start trouble shooting. Fluid is on, no leakage found and the pressure is good. I cannot hear the compressor turning on (idle stays the same, I cannot hear any difference), so no cold air is coming.

No fault with VIDA.

How to I determine if it is a relay, fuse or the actual compressor?
Can I test the compressor clutch?
I do not believe it is a electronic function telling the compressor "not to go on" since no fault is found with VIDA.

Note: 2008, V50, approx 120,000 miles

From your description, 99% its the compressor clutch gap issue.
Had the same issue last year but mine was engaging for a short while and then stopped working (with green AC button still active). Just compressor wasnt working but car "thinks" all is ok, hence no errors etc.

Whats happening is clutch on compressor gets worn out with years and gap needs to be nivelated - easy to fix by adding shims or bread clips or cable ties (in my case).

fingers crossed its the same for you.

[Clan]

Originally Posted by Ducatimatrix

Yet again the same question... I can see a lot of questions in this relation, but I am unable to find one that matches my situation

Basically I need to know where to start trouble shooting. Fluid is on, no leakage found and the pressure is good. I cannot hear the compressor turning on (idle stays the same, I cannot hear any difference), so no cold air is coming.

No fault with VIDA.

How to I determine if it is a relay, fuse or the actual compressor?
Can I test the compressor clutch?
I do not believe it is a electronic function telling the compressor "not to go on" since no fault is found with VIDA.

Note: 2008, V50, approx 120,000 miles

you can apply 12 volts directly to the clutch wire to see if it engages and gets cold , only do this for testing purposes . You can access the wire either from the connector near the pump or from the relay socket in the fuse box .

[Ducatimatrix]

Originally Posted by LizardOfBodom

From your description, 99% its the compressor clutch gap issue.
Had the same issue last year but mine was engaging for a short while and then stopped working (with green AC button still active). Just compressor wasnt working but car "thinks" all is ok, hence no errors etc.

Whats happening is clutch on compressor gets worn out with years and gap needs to be nivelated - easy to fix by adding shims or bread clips or cable ties (in my case).

fingers crossed its the same for you.

First thing first, clutch not engaging when AC turned on. More details after next suggestion. I did measure the gap and it was around 0.7 mm. Re-shimmed to 0.3 mm - so this part is now OK. Thanks for this point.

Originally Posted by Clan

you can apply 12 volts directly to the clutch wire to see if it engages and gets cold , only do this for testing purposes . You can access the wire either from the connector near the pump or from the relay socket in the fuse box .

Applied 12 V to the compressor and clutch engaging just fine. Checked the fuse "F27 AC Clutch" and all is good. Is there a relay somewhere? I guess this fuse is supplying the relay with 12 V and the relay is controlled from the engine computer? I measured 12 V (14.7 V to be precise with engine running ) on the fuse socket, so voltage is supplied to the relay.

I guess it must be the relay since voltage is supplied, no errors and the AC Clutch is engaging just fine (when manually supplied with voltage).

I read somewhere that there is a few sensors telling about pressure on the AC system, if one is not working the AC Clutch is not allowed to engage. I guess this will generate and error?

[Clan]

Originally Posted by Ducatimatrix

First thing first, clutch not engaging when AC turned on. More details after next suggestion. I did measure the gap and it was around 0.7 mm. Re-shimmed to 0.3 mm - so this part is now OK. Thanks for this point.



Applied 12 V to the compressor and clutch engaging just fine. Checked the fuse "F27 AC Clutch" and all is good. Is there a relay somewhere? I guess this fuse is supplying the relay with 12 V and the relay is controlled from the engine computer? I measured 12 V (14.7 V to be precise with engine running ) on the fuse socket, so voltage is supplied to the relay.

I guess it must be the relay since voltage is supplied, no errors and the AC Clutch is engaging just fine (when manually supplied with voltage).

I read somewhere that there is a few sensors telling about pressure on the AC system, if one is not working the AC Clutch is not allowed to engage. I guess this will generate and error?

Yes there is a pressure cut out switch in the line near the brake master cylinder ..

[LizardOfBodom]

Originally Posted by Clan

Yes there is a pressure cut out switch in the line near the brake master cylinder ..

..also that part is easily to check with VIDA - just few days ago browsing trough options I remember seeing this - can be tested if engaged/disengaged.

[The Thong]

I had this happen with my V50, it turned out to be a hole in the condenser and the pressure was too low to allow the pump to engage. See if it can be regassed so they can see if there’s a leak.

TT

[Clan]

Originally Posted by LizardOfBodom

..also that part is easily to check with VIDA - just few days ago browsing trough options I remember seeing this - can be tested if engaged/disengaged.

not sure whether it is monitored , but it is only a Gas or no Gas switch , short it out to bypass it for testing .

[Ducatimatrix]

I think I fount the fault

Shorted the 2 pin pressostat and now the clutch engage... So properly need to replace this one - unless the pressure is too low. The air is cool but not cold....

Where can I in VIDA see the pressure? I found in the ECM module the option to engage the compressor clutch - kind of cool and clarified that wiring, relay etc. was OK. But I am unable to find where to read the actual pressure.

What number do I expect for the readout? The actual pressure or a voltage / resistance from the sensor? What is the limit for not engaging the clutch, and what would be max pressure allowed?

(last question, what is the 4 pin sensor on the other cooling pipe for?)

Sorry for all the questions, work habit to know everything...

[Clan]

Originally Posted by Ducatimatrix

I think I fount the fault

Shorted the 2 pin pressostat and now the clutch engage... So properly need to replace this one - unless the pressure is too low. The air is cool but not cold....

Where can I in VIDA see the pressure? I found in the ECM module the option to engage the compressor clutch - kind of cool and clarified that wiring, relay etc. was OK. But I am unable to find where to read the actual pressure.

What number do I expect for the readout? The actual pressure or a voltage / resistance from the sensor? What is the limit for not engaging the clutch, and what would be max pressure allowed?

(last question, what is the 4 pin sensor on the other cooling pipe for?)

Sorry for all the questions, work habit to know everything...

The "pressostat" is a low pressure switch which cuts the compressor out when the gas pressure is so low as to no longer be able to carry the lubricant around for the compressor , the pressure is not stated but likely be just a few Bar, it may be stamped on the switch .

The 4 pin sensor is a variable output pressure sensor which reports back the actual pressure for operational purposes . It will shut off the compressor at 30 Bar if the system is overworking for whatever reason ..

Pressure reading is no indication of volume of gas left however .

you need to change the "pressostat" switch if you think it is faulty , see how it is , and if the performance is low get it checked for leaks and if ok then refilled with the correct volume of gas .

You can change the "pressostat" switch without draining the gas , you will just get a small puff as you undo the switch , it then seals .