My mechanic just replaced the compressor and serpentine belt on my V90. However, I never got to try the new ac because of the colder weather. After 2 weeks it got up to 70 degrees and I decided to turn it on. To my dismay my new and expensive ac was blowing hot air. I checked under the hood and could see and hear the compressor turning on and off, on and off the whole time.

My question is What is wrong now w/ the ac and also is my mechanic going to fix this for free or charge me again?

Hello, If he did the work saying it was going to fix the problem yes! If not, I guess you will be dropping another 60.00 to find out what is wrong. Pauli

Most likely a slow leak. When freon is low quick cycling is typical. Your mechanic should have been able to detect a leak when he vacumed it down before charging and after he charged it. In fact he should have thoroughly tested for leaks, that is part of his job.
Whether he charges you or not is up to you to a great extent. If he was careless or not thorough and is unethical he will surely try to charge you. Ask a lot of questions and get the answers then decide if you should pay him more.
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David Hunter

If the compresser is turning on and off it could be a couple of things-one there's a leak in the condenser or elsewhere-two it could be a high preasure switch. My bet is there's a leak somewhere and not letting the compresser stay on long enouth to make cold air. The system could have a slow leak that your indy might not have picked up on-with that said it's not his fault that with the parts he replaced didn't fix your problem completely.
Poolman

Hello Poolman, I'm sorry, but if he fixed the system, it would still have freon. I have to be very careful with my customers how they treat an a/c repair. Most are patch jobs which I don't garraunty, however, if I tell someone its fixed, its fixed and if they have a problem its on me. I guess I just have a higher set of standards. Pauli

Understand Paulii-Had hit a deer with my 960 and later after having fixed(hit the sucker head on about 60)about a year later the air wasn't up to snuff. Took car to an indy freind and recharged the freon and all was well. The next am the air was weak again. Then when trying to find the problem the condensor gave up the ghost. I couldn't or wouldn't expect him to pay for something like that-old parts give out. I understand where your coming from too-same guy replaced my ac compresser twice with OEM Volvo part twice before he got a good compressor and didn't recharge me-he goes the extra mile also--Thanks for good posts and all ways there with the help we need.
Poolman