If you can start it with the key out it sounds like the switch is bad. Get to the wires on the back of it and remove the ones leaving the switch and going to the fuses box. The lights should go out then.
Time and use would cause it to fail. I don't have a diagram for that year model so I can't say which wires would cause the problem. Don't quite understand what you mean by the pink wire turning them off and making them operate normally. If you disconnect the wire and they go out then they should not come back on with the wire disconnected. will it still start with the pink wire disconnected?