LuvmyAWD

The problem happens in any wheather and the sound comes from the middle of the car and yes i understand the RPM's move with the AC on but i mean i goes from the 1 mark to 2 lines above the zero and will do that for about 5min. and then it will eventually turn off the car...

I have had my edge for about a month and i LOVE IT!! well i got the 3.5L AWD, any ways when i turn my AC on my RPM's go up and down and there's like a "rattle- sounds like a snake kind of" and sometimes it will actually turn my car off since the RPM's go so low and i have had the C.E.L. light come on and it came on because the engine was idleing so low it made the C.E.L. come on, well thats a sum of whats up with my EDGE if anyone has the same problem or had the same problem could you PLEASSSEE!! help me i took it to the dealer and they said it was fine no problems but there is obviously a problem, so now i have no other choice but to take it to another dealer 3hours away which sucks.. SOO ANY HELP WOULD BE VERY AWWWWSOME!!! Oh and im new !!!