Anti theft device issue

[JimJamie]

My 1999 Forester usually starts ok. Once in a while nothing happens when I turn the key. I unhook the positive lead on the battery, put it back on and the car starts.

 

However there is a soft buzzing sound from the dashboard after it starts. For some reason there is a six inch wire hanging from under the dashboard. It has a tiny button on the end of it. I push it in with a nail or a pen and the buzzing stops. The car is fine for a few uses then will not start.

 

This car was my dad's. He says it has something to do with the anti theft feature. He is 89 and can't remember who installed the wire and button or why a real fix could not be done. The only Subaru dealer he uses has no record of the vehicle.