c5 aircon 2004 hdi

[zs&tas]

Hello, aircons stoped working in the middle of summer yay !
I went to have it gassed but it has made no difference, blows and lights on but just warm air. Where do I look for the pressure switch , im guessing maybe the compressors not kicking in. Any thoughts appreciated ?

[DickieG]

When the engine is running with the A/C turned on the front end of the A/C compressor should be turning in time with the auxiliary belt, the cooling fan should also be running, check on those items first to help diagnosis.

[zs&tas]

Just spent a few mins out there, compressors not kicking in. I cant easilly find a sensor anywhere, its tight and not sure where to look, I was just following the refridge lines around. Thought I might just put a manual feed on the compressor, I dont know what other consequences that might have though.

[kenhall1202]

Did your regasser do a system leak check before recharging the refrigerant?
Had my 2005 C4 regassed by KwikFit which lasted less than a year before failing again (waste of £50!). Solution was to perform a nitrogen pressure test (better than vacuum test) which confirmed that system was leaky. Alloy condenser had corroded in several places due to salt (UV torch showed up leak areas where fluorescent dye has leaked out). Your C5 is a similar age to my C4 so I would strongly suspect a similar failure.

[DickieG]

As the compressor isn't engaging then as mentioned it's quite likely that the gas has escaped, you can often spot leaks on the condensor by looking through the front grill for an oily patch which denotes a leak.

[zs&tas]

We sat there twenty mins with a pressure guage attached to say system full but the compressor was not kicking in I believe, im going to hot wire it and see if the system gets cold, does anyone know the location of the sensors, are they next to the condenser or some where else ? I will look through the grill to see if I can find them.

[xantia_v6]

The pressure switch is almost certainly mounted on the drier bottle, but if there is gas in the system your problem is probably that the ECU thinks that there is a fault in the cooling system or somewhere else. You probably need the car connected to a lexia to read the fault codes.

[zs&tas]

Ok thanks. Ill get it conected if the switch tests ok .

[dnsey]

I think the pressure sensor(s) must be more sophisticated than a switch, as Lexia allows reading of high- and low-side live pressures.

[kenhall1202]

On the C4 the pressure sensor is teed off the alloy pipework. Drier is not separate but combined with condenser.
Repeating previous posters suggestion a Lexia diagnosis would be helpful.

[zs&tas]

Thanks guys, I found the sensor. Hot wired the compressor for five minutes no cold, im guessing there must be a leak somewhere then just strange that the garage had it saying it had pressure for a while and still nothing. Maybe somethings not moving under the dash ? But then none of the aircon pipes in the engine bay changed temps either.

[zs&tas]

Sorry thinking out loud !