Nissan Repair: 04 Quest Airconditioning smell, mold forms, auto parts stores

Question
I have an 04 Nissan Quest.  I live in Texas and
have used the a/c daily since I've bought the van
new.  At the beginning of the summer, when I turned on the system, a terrible old rotten sock
odor would come out of the vents.  It would go away after a few minutes.  Ive replaced the in
cabin filter and searched for mold but still have
the problem.  Ay suggestions?  

Answer
John,

The evaporator core in the dash is where the smell comes from.  Mold forms in the box as a result of the condensate from the evaporator being cold.  Auto Parts stores sell cleaners for this.  Basicallly, with the system running you use the spray and feed it into the air intake.  On recycle it is done under the dash and if you have it on fresh air you spray it into the cowl, in front of the windshield.  You have to do it every month or so during the summer as the smell will come back.  Also, make sure the water drain on the airconditioenr box is open.  It is on the firewall, under the car.