Nissan Repair: electrical failure, nissan maxima, electrical failure

Question
What can make your electrical system fail and what needs to be done to fix it ?(pwr windows,lock,seats,radio,head and tail lights,have all stopped working)1986 nissan maxima

Answer
Sounds like the fusable link at the battery has burnt in half.  If this is not the problem it should be the ignition switch has gone bad.  You did not mention if the car still runs.  I assume it does and the items you mentioned do not work.  So, first check the positive battery cable and look where the fuseable links and fuses are tied to the harness there and then if that is not the problem look at replacement of the ignition switch.  Remember, when you start the car it diverts all power to the starter and then when you let off the switch and it springs back to run mode all the assessories function.  In your case these do not function so it is either the fuesable links or the ignition switch.