Climate control failure on 164

Guys,
I've got a 1995 164TS Super. It has the climate control with the digital display (where you set the required temp etc). Over the past week I've noticed the air flow getting weaker and weaker and now there's no air at all - can't even demist the screen.
Maybe electrical (but wouldn't that have gone instantly?) or is it the fan itself. Have read about stepper motors and gears. Any thoughts? Is it a dreaded dasboard out job?

Geraint