Toyota Repair: Have problem with my Toyota Liftback 1.8 1981, fusible links, negative cable

Question
Need to know how to fix the problem the light of the battery stays on and when I take off the negative cable the car turns off I checked the alterator with an electricmachanic and he said it is working ok I need help Iam desperate I dont know what else to do

Answer
The alternator is not charging the battery, check to see if this model has an external voltage regulator and try replacing it if it does, check to see if there is batttery voltage at the large terminal on top of the alternator with a test light, if there is no voltage at that terminal check the wires coming off the positive terminal on the battery, there are a couple of large wires which are fusible links extending about four inches before turning into regular wires, check to make sure these wires are not open. If there is voltage at the alternator terminal then I still would suspect that the alternator is the problem.