I have a 2004 Nissan Maxima 3.5 SE, and there is a problem with something running in the engine compartment after the vehicle is shut off and the key is removed. It sounds like a fan or something like that. But, the sound is coming from the area on the left side top of the engine. Near the intake, possibly behind it. If any one has any insight, I would appreciate because it is draining my battery.

 

i had a gold 92 maxima se A/T tho...
but yeah the ABS pump would run sometimes(it sounded like a coffee grinder)
so then after id park for the night or a long time
I would have to pop the hood,bang the relay area with my metal flashlight
and it would stop(not make noise)for a few days- i thought my wheels being the wrong size was making it see the "inner" tire spin too slow when turning sharply
i never got around to try swapping the relay under my 92's black cover next to the ABS pump,or trying correct size wheels out
might be a similar version of ABS on your 04'(them older ones were the "dads and grandpas" to all yous guys newer ones)

in the picture(sorry nwp but im using this for helping i think)
see the black box between the fender and the brake lines going to the pump
thats where i would fonzi bang on the 92 se,i think the relay was sticking
mine would stick/run after reversing while full turn more than other times
but would happen under different conditions too,the 3rd gen maxima has a ABS computer that blinks codes(funny when i read on a forum that a dude read the fsm wrong"must drive over (x) mph to get blinks/codes with car still on"
he didnt know you can drive to register codes,leave it running THEN get out pop trunk and look by 6x9 speaker for ABS computer (on 89-94)and read blinks...so he made his old lady ride in the trunk and read codes while he was driving,lol
"lock er in tha trunk"