I have a 2003 H2 and two weeks ago it started killing the battery in 4-5 hours. I mean so dead it would not come out of park and would not release the key. Had battery checked and alternator load tested. All tested good. Traced it down to the Driver's seat. unplug the harness to the drivers seat and the test light ( connected between the negative cable and the negative terminal) goes out and drain stops. Has anyone else had this issue? If i leave the harness unplugged the battery is fine.

 

check the seat for cables rubbing on the rails maybe a wire has worn through and touching metal. there is also a module under there it controls the seats the heaters and seat memory. there are also modules in the doors that work with the seat module.

 

i plan on taking the seat out this weekend and looking for that type of stuff. Everything still works on the seat and when its plugged in the test light blinks in a weird pattern. Really strange stuff