im having trouble with 2001 surburban

Hows it going ladies and gents, anyways im having trouble installing a radio into 2001 chevy surburban it has on star without

bose radio or should i say amp.This is my managers truck she got it install without the onstar module any ways she was telling that her battery keeps on dying out after she would leave the truck sitting out for 24 hours for the past 5 years so i told her i had a little experience installing a radio well when i opened it up the radio look find when it was installed but the weirds thing i seen was were the remote wire was running to,it was running to her fuses and i dont think that was done right.and then they scrpe allot of the wires that were i guess to the factory radio and then they ran the remote wire from one of those wires i told her it could of been the remote wire draining her baterry well i told her she need that module so could any one help thanks...........

Two harnesses are used for the factory head-unit.  The first harness is the large harness that has all the necessary connections.  The second harness has one pink wire in it, this is used to turn on the factory amplifier.  Most installers will connect the blue/white wire from the aftermarket deck to this pink wire.

As far as the remote going to the fuse box?  Only the original installer would know this.