Ok yeah that makes more sense to what I was seeing. I haven't really had reason to run the AC really, the car "fits me" better with the top open anyway lol 😁. I'll look into it more over the winter probably, but I may just let it go for now

 

It's very common for variable speed blowers that use a power transistor. Nearly every car with automatic climate control uses something similar.

The transistor is hot all the time and it controls the ground to provide the variable speed. Now it's all done with PWM circuits, but before those were common it was done with a Darlington transistor. Especially on the X300 sedans, there are many ignition switched ground circuits.