Intermittent ac problem

[cmsacrui]

I have a 57 1.5 dci megane. Since the spring started I noticed that the ac wasn't cold as it should be. I was advised to get it regassed. I took it to my local Renault dealer, who did the job, and the ac has run fine for the last few weeks. However the ac now only appears to be working when it wants to. When it is working it will continue to work until I switch the ac off. If I then switch it straight back on, the ac doesn't work.  So I took it back to Renault who regassed it again yesterday, however today the intermittent problem is still there.  Renault said that the system is working as it should be with no mechanical problems.

Does anyone have any advice?

[golfoscarbravo]

I have a 54 plate megane estate 1.5 diesel; the air-con has been checked by several garages and although it is fully gassed with no leaks, it only works properly every second time it is switched on. If it's not working, I have to stop the car, cut the engine, re-start and drive away... then it will work. But if I turn it off again, it will not re-start until I stop the car and re-start it again. So I tend to turn it on and if it doesn't work.... I know it will work next time I want it. CRAZY. But no-one can find a fault!

[davelowe]

Possibly the pressure sensor...

[manoman48]

I would also go with the sensor. The repalcements seem to be designed differently with metal internals rather than the original plastic. It sorted out intermittant problem with a/c and doesn't cost much to eliminate it if you buy from eBay.

[malky]

got exactly the same prob with my 56 1500dci have had everything changed at some time mostly under warranty but still every now and again the a/c decides its had enough and quits - then its down to a mate who has a clip diag machine and five mins later its re-activated and all is well again for a while these meganes seem to have a mind of their own