9300 carrier weather maker 9200. The blower will not run off the air blowing is not heated. I tuned off the heat at the thermostat, and fan will not stop blowing. If I turn the temp on thermostat above room temp it says heat on but no heat come from bents. IF I turn it below temp of room it note no heat on but fan keeps blowing CANNOT turn off fan except at electrical fuse bow. By tripping fuse to off. I changed the filter and batteries in the thermostat. Any suggestions