91 INFINITI M30 FAN PROBLEMS...NEED HELP??

[TBLEEZY]

FOR SOME ODD REASON WHEN I CUT MY CAR ON THE INNER FANS START TO BLOW COLD AIR THOUGH THE FLOOR VENTS AT A MAXIMUM RATE OF SPEED!!!EVEN WITH THE AC AND HEATING SWITCH ON OFF IT STILL BLOWS AND BLOWS AND IT IS EXTREMELY ANNOYING? IF ANYBODY HAS ANY IDEAS ON HOW TO REMEDY THIS PROBLEM PLEASE LET ME KNOW....I CAN USE ALL THE FEEDBACK I CAN GET ON THIS ONE IM STUMPED...