mine is messing up just now.

Heater worked on 2 and 4
Then would come back on all settings, then change again to only 4

Checked all fuses, no faults found
Replaced resistor with original ford part, problem still there, NO settings working at all now.
Checked motor, motor turning freely, not a hint of resistance.

Now, Turn the dial to 4 and put pressure on the switch, and it works, let off the pressure and it stops.. Only does this on setting 4.

I guess the single dial cannot be replaced? it seems pretty well sealed, i was going to try and fix it.

Limited tools at this time of night means I cannot get the radio etc out so stuck tomorrow in -4c with no heaters etc...