Easily breaking fan temp motor. Current limiter?

[tmvk-]

Hi,
In Finland we have problem in winter:
1 Heater flap gets some moisture to its seals
2 Temperature goes under 0`C
3 Moisture on seals freezes
4 I start my C5 in morning, still -10`C
5 Stepper motor tries to change it's position. The flap doesn't rotate with it.
6 This breaks flap's plastic hole (around motors opposite head)
7 Causes that fan blows allways only hot or freezing air.

I have thinked this could be easily prevented with current limiter. Could it be done for a stepper motor. Ecu should not know, at there is something.

[tmvk-]

Here is picture about this:

[lotusman]

u should clean those flaps seals