In the 6 years I've had my 1990 405 Mi16 the air conditioning system has been faultless. I think it was last re-gassed in 2002.(I know many of you question the need for it in the UK but personally I get hot all the time so I find it useful)
Today, despite the pouring rain, it was stuffy. So I switch the air conditioning on. First thing I noticed was a new hissing sound coming from the blower vents on the dashboard. There's always been a slight hiss but now it's a lot louder. Then of course the next thing I notice is the lack of freezing air. It's just regular cold air like on non-aircon cars. I cannot detect any extra cooling.

Based on the fact that...
A: this problem just suddenly happened (didn't happen gradually over days or weeks),
B: the compressor's clutch still operates when I switch on the A/C button (Albeit with less drag on the engine than before).
C: The radiator fans still operate with A/C switched on.
...can anyone guess what's the likely cause?

Could it just need regassing? I've no experience of aircon problems. I thought that leaks would cause a gradual failure?
I know it will need looking at by an aircon specialist but I'm just wondering from what little info I've been able to give if anyone might have an idea of the cause? I'd rather not be totally at the mercy of some aircon cowboy who'll replace more than is needed just to make more money.

Thanks
Kris

I don't think the system would engage the clutch on the compressor if it had no pressure in it.

Indeed, makes me wonder if the gas level is ok and some component has failed. Which could mean big bills and it's hardly worth it on such an old car. Unless this system is so old that it doesn't have that shut off thingy for when the gas is low.

If its any help,i'm now removin my air con as its not conected by belt. I don't know if it works but if you need parts you can have them for cost of postage.
Gavin.

Thanks Gavin, I'll have to get it checked out by a specialist and see what's up then get back to you. Yours being a 1992 car I wonder what gas was used in it because I think that was around the time they started using R134a.

sorry not the '92 but an '89 also on holiday for 2wks as of today so will catch up when i get back.

If there's no gas then the pressure switch won't turn on the compressor. But there could be enough gas in the system for the pressure switch not to trip, but not enough for the cooling to work effectively.

Good news!
I've had it re-gassed with RS24. He tested it for leaks but couldn't find any.

hey it might be thr a/c compressor gasket being damaged and needs replace with a custom made one, or the pistons could be damaged, but as an advice never use different ferion gas than what ur comressor is designed for because this will definately damage ur compressor, my a/c also suddenly stopped cooling today and i was really pissed and it's probably the gasket needs replacing and the compressor needs oil too inorder to work properly

If there is no gas the aircon clutch wouldnt operate . Second of all the gas can be changed according to what the condensor specifys . Peugeot 405 compressor is the same as 306/406/405 ph2/206 and a lot of other models in the peugeot /citroen range . If its your compressor I have one still mint removed from a 306 ph2 . If so tell me you shipping location and ill post the price .

Funny you should reply to this now because it's died again. Not sure what if anything I'm going to do about it but thanks anyway.