blower motor runs at low speed on heat setting
 

Is this normal operation in a W124 that the blower motor should not speed up in heat mode. e.g 30F outside in the morning with engine temperature at normal.

It blows plenty heat quietly and warms up the cabin to a very comfortable level of 70 which I set on the dial. Just find it odd that it does not speed up the blower to do it quick.

point to note is that the aux pump does not run - I had installed a set of undersized carbon brushes a year ago and it again is bad - does that have anything to do with this? On A/C in the summer it will crank up to LOUD hi speed to bring down the temperature..

Will it go to high blower speed if you hit the high speed fan button, and will it go to high speed fan in defrost mode?
Gilly

Yes it will go to high speed if I manually select the high speed fan function or select the defrost function even with auto fan setting.