Blower Motor on 3&4 only

[Asamaan]

I have replaced my Resistor pack about 2 years ago when it was only working on 4. Now it works on 3&4 only. I checked the Resistor pack and all resistors seem to be connected at least when I tested continuity for all 4 pins to each other. My guess it is something else, but what should I check for? I just noticed it about a week ago, but I haven't been using the car much, so it could have been there for a while.

Thanks
Al
91 535i