W116, Body and Interior Specific Aid

For years now we have had a terrible fan noise when the heater is engaged, and it's NOT the main blower motor. Finally, I found out about the Sampler Blower Motor, or Blower Sampler motor, part # 0 130 002 802. This component is not listed on the fuse panel, but feeds off of fuse #1. I've got to get to this motor, at least to unplug it, if not replace. Does ANYONE know where it is, or how to get there?
For those of you chasing a mysterious fan noise--yes, there is more than one fan in the car. And No, not everything is listed on the fuse box cover.

When it rains or snow collects on the car, my 85 300SD collects a BIG amount of water in the area behind the driver's seat on the floor. The passenger side (side of the battery tray) is completely dry. The sun roof seals are dry and need replacing. Could that be where the leak is coming from? I read there are drainage holes around the sunroof and they get plugged...? The car is 80% restored after sitting outside for about 13 years. The engine is a factory replacement, but after purchasing it from a wrecked condition, there were no written records of maintainence.

I will be replacing the front and rear rotors, should I also replace the bearings and seals? or is there a way to inspect them first?

While I have the calipers off, should I rebuild them? or is these a way to inspect them first?

Thanks,
Eric