Help!! Any ideas what is causing this parasitic drain? Mechanic is stumped. Dealer was stumped. Starter fine, alternator fine. Battery only 6 months old.

 

Perform a parasitic drain test. Videos on you tube.

 

Did either of the shops monitor the current draw on the battery once the vehicle went into standby, then consider what circuits are likely to have something on them that could cause that amount of drain, pull fuses for those circuits, and see when the drain went away? That's pretty much a summary of what the video on the subject will indicate. I'd suspect that the shop and dealership just didn't want to take up a bay for the amount of time it might take to find, and it seems not many shops actually enjoy working on electrical issues, so they may not have tried all that hard to find it.

If you or someone you know is handy, this might be something you want to do the legwork on, then once you discover what circuit has the bulk of the drain, determine if you want to take it someone to have it fixed or continue with the repair yourself. Are there any signs that your car has been wet inside before, such as from an open window/sunroof during a rain storm, or maybe a plugged sunroof drain?

-Rod