battery keeps dying

I have a 2002 Trailblazer LS.

My battery keeps dying. I can jump it off and its OK for 2 days then it dies again. The battery and all the cables have been factory replaced as a month ago the battery started bleeding acid all over the cables as it died.

Now, while the Trailblazer is cranked, I can disconnect the battery completely and the Trailblazer continues to run

2 Years ago I installed an aftermarket radio and amplifier. Ive never had any problems. So for troubleshooting, to make sure those items have not gone bad and are causing my problems I have removed all fuses for them, even the remote ignition turn on.

While doing this I fould a red wire leading the the fuse box under the rear-left passenger seat. This red wire had a large fuse in-line on it (no sure what its amperage rating is), and this wire is connected to fuse #33 (front wipers) this #33 is a 25amp fuse. What is this red wire for?