megane dynamique air/con problem

[Bearmana1]

hi,i have a 2005 dynamique estate 2 litre petrol 16 valve engine. I recently had the air/con recharged as it was not working,now on starting it works for about 5 minutes ,then the compressor stops running,it then kicks in for about 30 seconds,runs for about 1 minute before cutting out again and continues running in this cycle hence i get hot air all the time. i have found a small bore vacuum type hose that is disconnected around the radiator top area but i cant find anywhere it fits. i would be gratefull for any advice for my problem. thanking you in anticipation Alan