I posted a recent thread about both front wheel speed sensors not showing any speed via INPA. (replaced both with proper part no. bmw part)
https://www.northamericanmotoring.co...ng-thread.html

And now that i dig into I've noticed other electrical gremlins showing up thinking they might be related to some single electrical issue somewhere in the system.
I had a P1229 code indicating throttle body problems. Yet TB works fine (even did a successful re-adaptation using INPA just for experimentation)
And now i also notice that my cooling fan isn't coming on - but the diagnostics i've done show that it isn't the infamous low speed resistor problem (I read that entire 60 page thread). It seems I'm not getting a signal to the low speed fan relay in the engine bay fuse block. Throwing a multimeter on pins 85/86 shows no voltage when car reaches operating temperature or when a/c engaged. Shorting across 30/87 activates the low speed on the fan, which indicates the fan is functional - yay! Multimeter on the fan power connector shows constant 12V on the high speed circuit. Have to figure a way to get 12v across the relatively deep and small connector for the high speed relay (which is on the fan shroud) in order to test it (without shorting the 12v test leads!). Regardless, my fan does work but the car won't actually turn it on when needed. I've also switched around a myriad of 50A and 30A fuses found in the fuse block ( of systems known to work) and still no fan.
Pulled the EMS2K unit and it shows no signs of external damage.
No water around BCM connectors, and it has the black plastic cap over the top.
Connector to DSC/ABS unit looks intact (disconnected it, no signs of bent or rusted connections).
The only thing i've done recently is changed the stereo (from non-factory to another non-factory unit) - is it possible there's some sort of canbus issue?

I'm at a loss of what to check next.