The output of the coolant temperature sensor goes to the ECU, then as required the ECU turns on the fan relay. When the engine is cold go to the diAG screen and go to Code 06, read the value on the lower part of the display, this is the coolant temperature. Warm up the engine, shut it down and once again go to diAG Code 06 and read the coolant temperature. This will tell you if the problem is the sensor and if the ECU is reading the sensor. If Code 06 does not show the correct temperature you are looking at sensor/sensor wire/ECU issues. If the ECU does not read the coolant sensor due to open or short in the sensor it will default to 60º all the time.
IIRC, the wire attachment point on the sensor is exposed and could be damaged. If Code 06 reads correctly both hot and cold then you are looking at the fan relay, fan fuse or bad fan motor.
As mentioned in a previous post, the fan relay is up next to the battery. If you can find a Radio Shack they sell 20-30 amp toggle switches, this is the size switch you would need if you decide to follow road runner's suggestion. I would recommend 10 to 12 gauge wire, or if you can find lamp cord this would be more flexible and work fine. Lamp cord will have one of the two wires molded with ribs to help keep polarity straight. The liability of lamp cord is lower heat tolerance and chemical tolerance of the insulation. This is a field MacGyver, it doesn't have to be pretty, just functional.