Regarding the fan, I'm not sure how the 124 fan works. Something like when the AC high pressure switch is closed (compressor engaged), the fan comes on in low; when the coolant temp is above 105F, the fan comes on in high. I believe the coolant temp switch is wired to the high speed fan relay through the ACC PBU so anything is possible in terms of mixed signals. AFAIK, the temp sensor is not an on/off switch. It's a thermistor of sorts.

Sixto
95 S420
87 300SDL