I've done a search and there are a few threads but not sure from reading them where I should start.

I have a 56 plate vrs with dual climate. The blower was temperamental when I got it but now it's stopped working altogether. Won't work on any setting. The air con pump was recently replaced so I know that's fine... I just can't get any warm or cold air to blow.

Where should I start?!

bump

It would be worth checking the fuses. If it's gradually got worse it's probably something more significant, but I'd start by ruling out the trivial.

All my fuses where fine. I performed the Motor flap reset and gave the underneath of the glove box 3 or 4 hard , angry thumps and low and behold.................the fan started working again!!!

My mk1 went all temperamental when I was in the south of France one summer.  Turned out to be the carbon brushes had worn and the dust had clogged the grooves on the commutator.  A gentle scrape with a junior hacksaw blade to clear the gaps saw it back working properly.  Lasted until the car got scrapped.

I've kinda got this problem but whilst my blowers are still working, the fan unit or whatever it is makes a loud whirring noise. Guessing the whole unit needs replacing...