Almera SE 2005 with A/C.
On full blow the speed dropped to slow, then increased, then stopped altogether.
Have removed the blower motor and run 12V across the terminals -- motor spins.
Have removed and replaced the AMP unit with another s/h - no joy.
Have also noticed the 'outside' temp readout went to 49°C when switching on ignition, then reduced steadily to 23°C, when it's actually 11°C.

Stumped. Any clues?

Not a reply to myself, just a PS really;

There is no current to the terminal block that plugs into the blower motor, nor is there any current to the fuse in the dash (lower right). All fuses are intact, as are the fuses beside the battery.

This looks like a break in the wiring somewhere. Fun.

Also, disconnected th battery for twenty minutes (try anything). No change.

We don't have much explicit documentation on the Almera here in the 'States, only the '11 up which is basically a rebadged Versa. However, on any '05 Nissan product, chances are it's a brushed blower motor with a VBC (Variable Blower Control, Nissan usually call s it a Blower Amplifier). These all work pretty much the same way regardless of model, so maybe this will help you out with diagnosis:

blower-basics-t628180.html

Many thanks for the link. Doesn't tell me what's wrong - but does give a lot of explanation on VBC's. Looks like it's a garage diagnosis job.
Easy to forget many forums are Stateside especially from the UK where I am (Shropshire Hills).

Once I got used to the complex arrangement of buttons and display (a pain) for the heating/venting system, the whole system is pretty efficient. But the old slide for hot/cold; slide for screen/feet - has much to commend it.