Temp sensor: ECT sensor?
Resistor: looks like a coil of wire?

A/C will cause the fan to come on when a/c pressure is high independent of temperature. So that makes sense.

Confused here: "After driving with the A/C on, the car got warmer, and the fan speed went from high to low."

Low freon is the only thing that could cause that assuming that temp dial was set to LO (or cold).

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Regards . . . . JimF
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'94 S500 Cpe

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