Air conditioner problem and noise
 

Hello.

I have a trailblazer LT 2006.
Since last winter, there is a clicking noise like "drrrrrrr..." inside air-front vents or dashboard only for about 5 sec, starting car or turning it off.
When I change the direction of heat or cool air, it sometimes sounds.
These days, the cool air does not blow out from front vents no more. OMG!:eek:
But, it can do only from floor vent and back seat.
Searching the Internet, I am confused because someones are saying the exchange the ac compressor, but others are saying just cleaning the fan under dashboard.
In fact, I don't know about car well, so I would like to go to car center to fix it.
But, I would like to know the other good way or the exact reason about the problem. And, is it expensive?
Please help me!:confused:
Thanks for attention.

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Louis
GM Customer Service

Thank you for your help