There have been some models where the heated jets have malfunctioned and overheated. I guess cutting the wire is the cheapest way of solving the problem.
Check the operation of the door switch for your courtesy light.
I'd be surprised if a 14 year old alarm system was still working. Ditch it and get a modern one fitted.
Either the outside temp sensor has failed, or the wiring to it has failed.
All these problems are related, but only to the age of the car and the fact that fixing minor problems like this adds to the cost of ownership without making the car any more driveable or reliable.