I HAVE A 1992 CADILLAC SEVILLE(4.9LITER) AND WHILE RIDING ALONG HOT AIR WILL START BLOWING OUT OF THE HEATER/AC VENTS WHILE THE HEATER/AC CONTROL IS OFF ONCE THIS HAPPENS I TURN THE CONTROL ON AND THEN BACK OFF AND THE HOT AIR WILL STOP BLOWING DO ANYONE HAVE AN IDEA OF WHATS GIONG WRONG