i've had a dead start from the battery 3 times in the last week..so i figured the batter was no good, and i went on a tried a different battery..and still when i went to my car today, nothing was working, no power lock, window etc. So after getting a boost and running my errands, i came back home and i turned off the car, however, even after i took the keys out, the heating buttons/ac were still lit up and i was able to turn them on/off with the car completly off. I'm pretty sure if i don't touch the car for 10 hours and went back to start it up, the battery would be drained out.

so my question is, what's causing this problem?

 

Check Grounds, to frame, starter and alternator.

Also did you try a new battery or was it used?

 

connections on the battery itself? not tight without booster clamps?

 

i tried a used battery; and a new breakthough, my heating works with the car completly shut off