My heater on my 05 LaCrosse does not blow could this be a fuse?

It is either a fuse that has blown out or the blower motor has failed and needs replaced or the blower motor resistor.

It could be what csubak30 mentioned, and also possible damage ac control unit.

My 2010 Buick LaCrosse is doing the same thing. It won't turn off or change the settings. Neither increase or decrease the air speed nor will allow me to change the temperature up or down. It blows air at the last setting I had it on before it started malfunctioning. The air conditioning light is on even though it started malfunctioning during the end if the winter (meaning I wasn't using the ac). Following post for newer modules.