It's starting to sound like it may be just the blower motor starting to go out. Turning the key off/on probably just "unlocks" it when it hangs up. Sometimes connecting the blower directly to a 12V source can even be deceiving.

Have you pulled the blower motor and just inspected the armature and brushes? I'm not sure how much of a job it is on your car (mine comes out in about 15 min. or less) but it should be less trouble than pulling Pushbutton Controllers.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )