first I'd check to see if it has an alarm that someone else installed and then disconnected. check for some kinda random plastic box wired into shit under the drivers side dash, by the fuse box.
if not... get a test light out, take one of the battery cables off, connect the test light between the battery tremnal and the cable you took off. if you have a drain, it will light up bright. then pull the fuses one at a time till the light goes out. that will atleast norrow it down for you.
lots and lots of things can go bad and cause a draw. anything from a radio and hood lights to the computer itself... but that's very rare.
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