[Citroënbender]

I’ve seen how cheap they are, and seen the kits to use with laptops, it’s a hangup to want one of the old school units in tidy, calibrated form. :-/

The icons on that circuit diagram indicate the unit function relates to (is influenced by / interplays with) water temperature and AC.

I still reckon it’s massive overkill by the maker to use this on a 1.4 litre “city commuter” car. My Alfa simply has a resistor on the low speed and toggles with a relay. It’s never overheated when the fan is working (once when the fan was literally jammed against the radiator post-collision, it did get warm until it selected high speed and self-clearanced).

Just as a side note, the fan is Faurecia brand (the successor to ECIA components) and the control module Sagem.