Phalcon51,

I've done the blower motor replacement on a 1991 W126 (420SEL), so it may not be identical, but it is probably similar. In my case, the location of the blower motor is up above the footwell area for the front passenger.

My symptoms were that the motor first started to make some ticking sounds, and seemed to be running slow. I removed it, cleaned/oiled the bearing area, thought about cleaning/filing the brushes, but didn't see any easy way to remove them. So, I put it back in, and it ran OK for a few more months. Then it gave up the ghost entirely. I bought a replacement motor, without squirrel cage, since it is quite a bit cheaper without the cage.

removal/replacement is pretty straightforward. In my case, I had to carefully pry out a trim piece, to get access to the screws that hold in the padded knee bolster. Then, there are a few screws to remove to allow the plastic cover over the motor assembly to drop down. This cover also has the so-called "porcupine" assembly on it, and also has some wired going to it, so you need to gently move it to the side while you unbolt the actual motor and squirrel cage. Remove the two wires to the motor, and it's out.

Separating the squirrel cage from the motor takes a bit of banging, as it is a tight press fit onto the end of the motor shaft. I found that setting the squirrel cage on top of a solid support, but with an opening in the middle of the support so that the actual motor can hang suspended in the opening, allows you to use a nail set (or even a Phillips screwdriver, in a pinch) to pound on the end of the motor shaft, through the little hole of the squirrel cage mounting area. You really have to bang on it to free it - a little Liquid Wrench or other penetrating oil might help. The trick to not breaking the squirrel cage is to have it evenly supported around the perimeter of the cage - otherwise the plastic is pretty brittle and you can easily crack it.

Good luck!