If you did wire up a sub and amp setup, i'd disconnect it from the power source one night and see if that makes a difference.

 

I'll pop out my big fuse tonight and check back in the morning

 

I had the same problem after installing aftermarket stereos in two Impalas and my Monte Carlo. The problem each time was caused by the integration module that you're supposed to buy in order to keep your door chimes and whatever. I ended up using just the wiring harness portion of it (cuz you need something to plug into the car's harness) and scrapping the rest. If you used one of those modules, that could be causing the drain. Even when properly wired, they are trouble.

 

Well, i've pulled the large fuse that feeds my subwoofer amp, as well as the heated seat relay and the 15amp fuse for the lh heated seat/bcm and the car still drained down to 11.11 volts. I did buy the good wire harness with the integrated door chimes. Maybe i'll try to pull that and see if that helps. Any other ideas? I'm at a total loss here.

 

I've tried to pull my 15amp radio fuse overnight which should have killed the door chime unit correct? Still the same result. Drops about one volt in 10-12 hours

 

I don't have any more ideas, but i think i'd focus on the stereo install. Lots of odd things can happen when you install electronics.

 

I'll tear the dash apart and try unhooking the door dinger and see if that gets me anywhere. For now, i'm going to put a battery disconnect switch in place to try and stop harming the battery. Not real sure what else to do

 

I have a feeling that the integrated door chime unit still draws power with the radio fuse out. It seems like I still had issues... I would unhook it... Maybe reinstall factory stereo to see if problem goes away. I ended up cutting the door chime unit off the harness so i could still use it as an aftermarker wiring harness. I only used the wires that go to the radio. If i recall correctly, you won't have ignition switched power... Just continuous power (yellow wire). I tied my Red and Yellow aftermarket wires to continuous power from the "modified" harness. Fortunately my stereo has a power button, so i just turn it off when exiting the car. Otherwise, you'll need to wire a separate power switch to the red aftermarket wire to turn off the stereo.

 

How new is your battery, I had a relatively new Red Top Optima and it always discharged, kept thinking it was a parasitic discharge, replaced it and no more problems. So if yours is getting old, perhaps have it tested it may be the culprit...

 

I replaced the battery 2 weeks ago. I also load tested this one last week just to be certain