are your keys in the ignition and the door open? Hows your ignition. I know on mine when i take out the key, because its loose, it is slightly turned and acts like the key is still in the ignition. Are your lights still on when the door is opened? does it happen when youre driving? maybe your overheating. my 88 with a digital dash, beeps when it gets hot. Only happened once though. I hope this helps, as everything is helpful. good luck