The FAN DOES NOT STOP - C230 - 1997

hello, the engine cooling Fan does not stop.

I changed the Fan control Unit, - square fined aluminum box - and nothing happened, all circuits are ok.
let me know what the check,

help.
Thanks
Peter

fans in front of the radiator is controled by the climate control head, using the fan control unit
fan behind the radiator is controled by the engine control unit, using the fan control unit.
testing voltage at pin 5 on the fan controler, low voltage low speed high voltage high speed. get a wiring diagram, if wiring is ok, you may need a scan tool to test further