sc400 battery drain

[radicalblurr]

I have a problem with my battery draining. It will sometimes hold a charge over night then other times it will drain within an hour or so. The CD changer also behaves erratically, but i have tried unhooking the CD changer and the amps, i have also pulled the main fuse for the stereo - not the secondary 7.5 amp fuse yet. i recently purchased this car and it has a new antenna and the CD & tape buttons won't switch sources on the stereo. is it possible that the stereo is draining the battery? also i noticed that the remote door lock stopped working as this problem became more regular and never noticed that the security light ever came on when i shut the door. i have also turned off the remote lock switch since i read that it could drain the battery.
can anyone give an opinion?
my next step is to remove the stereo entirely to see if that helps, if not i'm afraid that i will have to go connection by connection to locate the drain.
1994 SC400 btw.

 

[sideshow]

make sure battery is charged up properly
then over nigth remove neg terminal so battery has no drian on it from the car

reconnect it next day and see if battery is good and starts car easy
maybe try it afew days in a row

if battery seams fine then its not a bad battery
as u said sometimes its afew hours other times its over night
so u need to see if its just a dud battery

then u need to get an amp meter
u can get new fancy ones that plug into the slot where fuses go
then u need to remove a fuse then plug this in and it will tell u if there is any current draw on that circuit
takes along time to go thru all fuses but if its on the std wiring cicuits then
u should find it on one of the fuses

on late model cars its very very hard to find current draws due to soo much crap and wiring
and if paying someone to find it dont get a shovk when the bill is over 500 bucks maybe even 1000 if the dash has to come out