2001 x5 wont start all the time

[mgeist]

any ideas or suggestions would greatly be appreciated.

i got an x5 about 5 months ago the last two months it has been acting weird it wont start (dead battery)

i replaced the battery and had the alternator checked nothing.

sometimes the battery will last a day sometimes a week i never know. i dont do anything different when turn it off. ie: turn off radio or air since thats all controlled from the ignition.

mods i have done are add a trailer hitch with bmw oem parts which included the wire harness and control module

added an amp with a remote turnon wire from the bmw amp. i have disconnected both the new amp (i added) and the trailer hitch and same thing sometimes it lasts a day or two others a week.

does anyone have any ideas i can try before taking it to the dealer. dealer wants 180$ an hour to find the problem they said anywhere 1-3 hours then replacing the part or moduel and that could be anywhere from 100 to 1000 but at this point i have no other option or choice however i dont really have the money either but also need a car

thanks!