What could cause the air from the air conditioner to suddenly became cool not cold in a 2001 VW Beetle?

Answer 1

On top of the battery box is a small electical connection box with fuses. I had an issue with the first fuse on the left. It had a bad connection which had melted the plactic fuse box due to the bad connection. I cleaned the connection and the fuse terminals and then reinserted the fuse. It was a quick temporary fix, but I replaced the fuse box to fix it permanently,

Several things can cause this. One is that the refrigerant is low and 2nd, the air mixture door is not operating properly. Goodluck, Joe

Mine is a "99" and started doing the same thing. Especially when I slowed down or came to a stop. Finally the cool air turned to normal outside "hot" air. So I took it in to one of the most reputable A/C shops for their diagnosis. Well - to my dismay - it was the compressor. It still had plenty of coolant and everything else was fine - the copmpressor just quit working. The shop told me this seemed to be a defect of the VW A/C system, because mine was the sixth one in the last month they had seen the same problem.

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So it may be wise to start saving your money - mine cost eleven hundred dollars to replace. $$$$$$

Another less common possibility which I experienced first hand is there is nothing wrong with your air con but rather the onboard computer is automatically switching off the air con to reduce the engines load because it is sensing the motor is overheating.