1st and 3rd radiator fan stage are caused by the radiator thermoswitch. 2nd stage by AC high pressure switch. 3rd stage will also cut out the AC compressor clutch. But I haven't ever seen this 3rd stage working due to high temperature.
Bevore I've converted my AC, I checked all these stages by shorting the switches and all worked as discribed in Bentley.
If ambient temperature is 80+, second radiator stage runs often at higher rpm.

Conrad
86GL

-----Urspr�ngliche Nachricht-----
Von:    Ari Ollikainen [SMTP:Ari@OLTECO.COM]
Gesendet am:    Dienstag, 4. August 1998 03:40
An:     Vanagon@VANAGON.COM
Betreff:        How hot is HOT?

        Thermoswitch for radiator fan     Stage I       Stage II   Stage III

        Cut-in temp                       89C-94C       95C-100C    ??
                                         192F-201F      203F-212F

        Cut-out temp                        81C            87C      ??
                                           178F           189F