My ‘08 R320 CDI has started doing something very odd...

I replaced the battery under the pass seat and now the hvac blows hot HOT air through defrost no matter the hvac controls are set at. I can have it in auto, off, floor, a/c, etc. the motor just stays on. It’ll start doing it about three seconds after you turn the car on, either running or not. It is NOT doing the more usual fault of blower motor running with the car off.

The only other thing I’ve done is spend three days cleaning puke out of my car from an extremely intoxicated passenger. That involved removing the pass seat( replaced batt at that time since it needed it) and taking most of the console apart. FYI: yellow curry stains carpet.

Perhaps I got something wet while cleaning, I’m not familiar enough with the R-class to know where the blower/hvac modules live. But I’m my experience with older MB’s, the only real thing living under the console is the abs sensor.

I also had the car running after the batt install so I could run the heat while working on the puke in the cold. I don’t recall it acting up at that time.

Any ideas? Or at least some wiring diagrams.

Thanks