What could be wrong with our A/C system when the blower will not shut off?

How do I shut off my blower in my home, even after it reaches the set temp it continues to run, we changed the batteries in the digital
Thermostat and it continued to run.

My A/C Blower will not shut off, what is wrong?

If the thermostat is on auto and the fan will not shut off the blower relay is stuck and needs to be replaced. Sometimes you can tap on it and it will free up as a temporary fix. But it will need to be replaced