Air Flow Drops Slowly Practically to Zero

COMPLAINT:
After long, uninterrupted driving in cooling stage, the air flow drops slowly practically to zero, while blower (automatic) can he heard at high speed.

Cause/Remedy:
Evaporator iced-up.
Check function of ETR-switch. Compressor should switch off at 0 ± 1 °C evaporator rib temperature.