Aux fan on 201.128 chassis is tripped by the high pressure switch on the a/c
The engine coolant temp fan is an electric clutch fan mounted to the water
pump shaft and is tripped by the 100C
temp switch . This can not be energized with the key OFF.
If you look at the two switches at the drier [ behind the left headlamp], one
has spade connectors and the other has 2 short leads
and a plug. Unplug the one with the leads.
[ The other one is for compressor cut-in]
If this stops the fan when it gets hot next time , I suspect the switch , But
, I have seen them cut in when the a/c system has been converted to freon 134A
and/or over-charged. [ caused by high side pressure reacting to ambient temp]
This circuit is alive regardless of key on/off position.
This easy test will tell if the fault is in this circuit.