OK HELP, I'm at wits end.
I thought for sure this was the alt with a bad diode as I've been a victim of this multiple times in the past. I pulled the alt and hooked bat up, same thing dead next morning. No interior lights to blame. No electrical changes in the last 2 years. Suggestions?
Interesting problem!!!
Check and see if lights in the trunk, glove box and under the hood stay on.
No trunk or hood light, glove box is maybe.
Remove the negative battery cable. Hook a test light between the negative battery cable and the negative battery post. If it lights, you have a battery drain.
Disconnect stuff and pull fuses until you can isolate what is lighting the light.
say what?! that's definitely a new 1 to me
By disconnecting the negative battery cable and using a test light you can unhook electrical stuff and fuses one by one to try and track down the drain a lot easier. Example, You remove your negative battery cable, jumper your test light from the negative battery post to the disconnected battery cable and it lights up(shows you your drain), you pull fuse 12 and recheck your test light and the light goes off..... so whatever is running off of fuse 12 is causing your drain. Very very nice for finding a battery drain.
I had a similar problem once...was a rear defrost relay...just pulled it and added a quick disconnect to the battery for when I needed rear defrost again.