Whew! That's good news - most likely just a bad resistor. It's located near the receiver / drier behind the headlight, below & behind the ABS pump, towards the outside of the car... a real bugger to access. The ABS pump has a black plastic cover, the resistor is pretty much directly below the "S" in "ABS". It's roughly the size of your thumb, it's (dirty) white ceramic with a black metal bracket wrapped around it that may say "Behr" on it.

With the red switch jumped, if you get +12V on one side and nothing on the other, the resistor is bad. Or measure resistance across it, should measure something quite low (say, under 10 ohms)... if it's infinite or very high, it's bad. If you jumper the resistor to bypass it, the fan will run on high when the AC pressure is above 16 bar. This may improve AC performance a bit at low vehicle speeds, the drawback is more noise, a bit more wear on the fan, and increased load on the wimpy stock alternator (especially at night with headlights on).