Big problem!!!!

Hello to all of you here for the first time… My girlfriend bought an Escort CLX Kombi for 650€…the vehicle still has TÜV and HU until 5/2010…there were 4 new summers and winter tires. And now to my problem, the rear left door does not open, neither from inside nor from outside…despite the doors were opened or closed with the central locking. Then you turn off the engine and it stays on anyway???? In addition, when I have light on and on the brake there is no Br the rear light unit…the reverse gear functions perfectly from the light signal…or when light is on and you brake the number plate lights on and when releasing also against off…what is that, and how can I fix it? Ohso, the dare is from 14.06.1991 Greeting Daniel