ok, so there are a mess of things wrong with my car, but my main concern is what is occuring lately. when i drove and turn the car off, there seems to be some sort of noise coming from under the hood that sounds almost like a vacuum cleaner sounds. i don't know if it's a pump of some sort, or if its a fan? i looked under the hood last night as it was happening and the two fans in the front were not spinning while this was happening. it eventually stopped and started again abou 30 - 40 minutes later and happened at least 3 times while i was awake. well when i got up in the morning to start my car, it was completely dead. no mileage, no clock, can't even pop the trunk. so did this mysterious vacuum suck my power dry and what is it?????????????????????????????????

What year and engine. SOunds like the secondary air pump is coming on. The relay is under the dash on the drive side relay number 52 I believe on 99.5 and newer.

What year and engine. SOunds like the secondary air pump is coming on. The relay is under the dash on the drive side relay number 52 I believe on 99.5 and newer.

it's a '97 jetta and it's something underneath the hood. whatever it is it's located in the middle attached to the front of the engine and looks like it ties into the air cooling system somehow. any help??

Yes thats the secondary air pump. the relay for a 1997 is next to the battery. That relay/fuse bracket on the fender area. when the pump comes on pull that relay out and see if it turns off, if it does replace the relay. Sometimes the contacts inside get rusty or corroded and cause the pump to come on randomly.