Excess Wind

My '95 Bonneville has push button electronic climate control, When I turned off the A/C, the the system automatically switched to the floor, blowing air with the fan speed on high. When I got home the fan kept on running on high.. Even after the key was out of the ignition!. The only way the fan would stop.. was to disconnect the battery. The A/C will come on when I push the button .. but return to the floor on high when I try to turn it off.
Is there a solution to this short of tearing the old control panel out and replacing it with a $535 new one.?