Update on my fan failure, as Taxi Driver says, 12V at fan output of controller when open, 0 when fan connected.
Tried another controller, no change. Now it gets interesting or confusing.
It dawned on me that I was doing these changes with F33 in place, so power on to controller. Powered the system off completely, then connected a headlamp bulb in place of the fan, refitted F33 and.....
Lamp at varying brightness with fan speed selection, current draw up to 3A or so.
Refitted fan, speed controllable, draws up to 6A at max available setting. Same with both controllers.
I don't really know what conclusions to draw from all this, the only changes were lubricating the motor bearings and refitting the controller with power off.
Fan motor no longer squeaks, plus point.
Running current is up to 6A or so.
For anyone attempting a fan change, it's a heck of a lot easier to remove the air duct if you remove the passenger's air bag and its mounting.
The only other information is main dealer in Bristol has three controllers in stock with a significant usage rate.