Technical 100HP air con clutch not engaging?

[RayovacWorkhorse]

Hi all,

My friend has just bought a lovely 2010 100HP with the electronic climate control (that seems to mostly work) and we are just ironing out some of the small issues that it has. One issue is that the air con doesn't work, light comes on and that's it! I know this could probably be for a few reasons (no gas in it, faulty compressor clutch, etc...), but something I noticed was that on the gauge cluster, the ambient temperature readout in the bottom left simply shows "--C" (unsure if this would cause a problem). We're giving it a good going over on Sunday with a full service and some other bits, but I don't quite know where to start with the A/C, does anyone have any tips?

-Charles

 

[PuntoHowTo]

Hi all,

My friend has just bought a lovely 2010 100HP with the electronic climate control (that seems to mostly work) and we are just ironing out some of the small issues that it has. One issue is that the air con doesn't work, light comes on and that's it! I know this could probably be for a few reasons (no gas in it, faulty compressor clutch, etc...), but something I noticed was that on the gauge cluster, the ambient temperature readout in the bottom left simply shows "--C" (unsure if this would cause a problem). We're giving it a good going over on Sunday with a full service and some other bits, but I don't quite know where to start with the A/C, does anyone have any tips?

-Charles

Climate control will use the information from the exterior temp sensor so it could have an impact, but if the light is comming on it suggests the ac demand is being responded to and it’s just not kicking in the clutch

If you have diagnostics software like MES you can check the pressure in the system.

Some people might open up an ac fill port and check if there is any gas pressure in the system which is of course highly illegal and I could never condone that. (Environmental health laws on releasing refrigerant)

If you could establish if there is gas in the system then the next thing you could try is manually activating the compressor clutch with a 12v feed and see if you get cold air in the cabin….

Experience tells me it’s probably most likely to be low/out of gas and need a refil. Quite often the reason for this in fiats is a hole in the condenser from corrosion or a stone hitting it.

 

[RayovacWorkhorse]

Thanks for the reply, aye my primary thought is that it probably has no gas in it, I'll have a gander at the condenser and see how mullered it is/look for oily residue before I recommend taking it to a garage to have it tested/regassed. As for the temperature sensor I think it it's in the N/S mirror and eper doesn't show it as a separate part so I'm hoping I can get away with cleaning the connector! If I have time I might have a go at jumping the clutch to see what happens.

 

[koalar]

Almost certainly need cutting out and a replacement soldering in

Touch over £5

Not a panda but very similar from memory



Unclipping the glass can be tricky as you are working blind

 

[RayovacWorkhorse]

Gave it a full service and it's running good (oil, plugs, air, gear oil, etc...) We had a look around it after and the condenser looks alright (who knows if it's holding gas though). Poked my head under the mirror and the sensor isn't there, just a hole where it should be! Moved the glass so I could just about see in there and it doesn't appear to be rattling around inside either. The plot thickens...

 

[koalar]

Gave it a full service and it's running good (oil, plugs, air, gear oil, etc...) We had a look around it after and the condenser looks alright (who knows if it's holding gas though). Poked my head under the mirror and the sensor isn't there, just a hole where it should be! Moved the glass so I could just about see in there and it doesn't appear to be rattling around inside either. The plot thickens...

As per post 2

Do you have any diagnostics

Most scanners/software can read the pressure sensor directly

 

[RayovacWorkhorse]

As per post 2

Do you have any diagnostics

Most scanners/software can read the pressure sensor directly

I've got a cheap OBD scanner somewhere

We're gonna try taking a look at the ambient temp sensor first (considering it seems to be absent!). If the wires are there I'll solder a new one in, if not, guessing it's got the wrong mirror on it. If that's still no good I'll get an a/c machine hooked up to it to see if there's anything in it and pull a vacuum to see if it holds.