Nissan Repair: 95 altima AC & brake lights that wont go off, charging system, expansion valve

Question
My AC is fully charged and has no leaks but after 15 mins of driving the temperature goes from ice cold to hot.  also the brake lamps stay on constantly until the battery is disconnected or goes dead.  Thank you for any help.

Answer
Darchie,

There are a couple of things going on here.  First, let's address the charging system.  Get the battery fully charged and then install it and drive the car to Checker or Autozone for a free charging system inspection.  This is probably going to show that the alternator is defective.  The second thing is the airconditioning.  If, after fifteen minutes, the airconditioner goes off would lead me to think the system could be over charged and after the system thermally loads, gets hot, it is tripping the pressure switch so the system will not blow a hose.  Have the system pressures checked after ten minutes and see if there should be some R-134 that needs to come out.  There is a table that tells the system pressures.  I cannot imagine the expansion valve acting up after fifteen minutes.  These usually fail and nothing works.  So, the running for fifteen minutes is the tell.