So this morning my W124 started making an annoying whine behind the dash. Seems to be coming from the passenger side, so I suspect the sampler fan is going bad. Blower motor is brand new, and the whine is more or less continuous, and is independent of HVAC operation - i.e., it's the same regardless of fan speed or vents selected, and remains even if the AC is switched totally off. Does this sound like the sampler motor?

My main question is do I need this thing? It doesn't look too expensive to replace, but my AC doesn't even work (won't hold Freon), so what's the point of automatic climate control? If I just eliminate the dying fan, what's the harm? Some sort of vacuum leak?

I wish this car just had a simple manual system instead of this overcomplicated garbage...