You have an electrical short somewhere in the car, and it's what is draining the battery. Put a lightbulb inline with the battery (between the battery and the negative cable). You should see it light up. Get your fusebox diagram out and remove the fuse for the radio and any security system (since power always runs through these). Then remove each fuse one by one, and watch the bulb. When you pull a fuse, if the bulb stays lit, that's not the one you want. Put it back and pull the next one. When you pull a fuse and the bulb goes out, you've found the circuit that is conducting and causing your battery drain. From there, you have to troubleshoot the circuit to find out which component is failing.
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You have an electrical short somewhere in the car, and it's what is draining the battery. Put a lightbulb inline with the battery (between the battery and the negative cable). You should see it light up. Get your fusebox diagram out and remove the fuse for the radio and any security system (since power always runs through these). Then remove each fuse one by one, and watch the bulb. When you pull a fuse, if the bulb stays lit, that's not the one you want. Put it back and pull the next one. When you pull a fuse and the bulb goes out, you've found the circuit that is conducting and causing your battery drain. From there, you have to troubleshoot the circuit to find out which component is failing.