X5 E70 N55 electrical burning, randomly started

[snazycummins]

Couldn’t think of a weirder thing to happen but we were out grilling in the backyard yesterday and we all got a width of a burning electrical smell. so we looked around all of the cars and the X5 was humming and making a tink tink tink sound but the car has been off and parked for 10 hours. Sure enough something under the hood was running and the right below the airbox at the throttlebody was extremely hot. It sounded like some kind of auxiliary fan might’ve been running. It’s an N55, but it does not have a remote start so I don’t know how anything could’ve possibly been running while the car had been off for 10 hours. I pulled the negative cable off in the trunk and the car shut down, and the battery was completely dead the next morning. For reference, the battery was changed a week ago along with the water pump and I used the foxwell nt510 to register the new battery. No codes on the scanner except for A open circuit to a blown speaker in the passenger side rear door. I’m so beyond confused on how anything under the hood or in the system could be running and I not have noticed it for 10 hours.

[tomjonesBT33]

ISTA-D has an ability to monitor current draw from various ECUs on the car. I’ve never used the feature, but google it and there are some videos on how to do so. That might get you started in the right direction with determining the system at fault

[snazycummins]

Fun update
https://www.dropbox.com/scl/fi/r0flx...6cdp9frpv&dl=0
https://www.dropbox.com/scl/fi/ve983...87v93y458&dl=0
https://www.dropbox.com/scl/fi/d865k...yv3g6jk7k&dl=0https://www.dropbox.com/scl/fi/ceqjb...pegz39fei&dl=0

Looks like it connects the starter to the water pump. Pulled the plug at the back of the water pump and everything looks fine. Best way to test if I have a break in the line or it’s shorting somewhere?