Is there only one thermal switch for the radiator fan in the 92-95 900 cars?

I've perused the manuals and I can't seem to find another source for trigger of the cooling fan. If that's the case, I've been marveling over how STUPID a design it is to put the coolant thermoswitch in the TOP of the radiator, where it's soon out of water if the coolant goes low. That's why I'm wondering if there is another switch for the fan such as engine temp or something.

I might be missing the diagram that shows the real truth, though, but my manual supply is restricted because I'm at home right now.

My own car doesn't seem to turn the fan on at all when idling, unless the A/C is on. If I jump the radiator switch it runs the fan on position 2 (hi), so the relay/resistor circuit works. And of course the fan works. The A/C runs the fan on position 1 (low) at low speed/high pressure in the condenser.

But is there another sensor that runs the fan for engine temp, or is the upper radiator switch the only one?

Also, if that's the case, is the radiator switch the same as older 700/900 (pre electric fan models) or is it a lower temp thermoswitch? It seems dumb to wait until the radiator is running at 205° before it turns the fan on.
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1992 940 wagon, 72k