I have had it back to the ford dealer who have replaced the air con pump/unit under the bonnet, didnt fix the problem, they have just replaced the pressure switch... this also didnt work. I have had the system completely drained of gas and purged then re-gassed. It stopped flashing for 1 day then started again. I am at a loss now as to what is wrong with it. Surely if there was a leak it would have showed up when the system was purged.