E39 2002 Blower Motor

Exactly one year ago I had my main blower motor (under dashboard) replaced along with the FSU module. Now the same problemhas arisen. Basically it just stopped blowing. At no speed ever. The old blower looked all dirty and the fan itself only turned with difficulty. I just wrote it off to age. Not sure what or why this has happened again. I've checked the main box fuses and nothing seems wrong there. I couldn't get at the 2 fuses larger fuses behind glove compartment. I surely don't want to have to replace the fan again but I have no idea why this is happening. We can feel cold air moving throughout he system though so I know the A/C is functioning.

Anybody else have this happen? Or a clue why?

Thanks.

2002 E39 530D M57 Touring.