2008 Trailblazer blower

I have a 2008 trailblazer that the ac/heater doesn't always come on. When it does come on it wont stop blowing until the battery dies. Any ideas on what could be wrong is greatly appreciated.

Thank you :)

Maybe an issue with blower motor control module?

Caused bythe blower relay/resistor under the dash just left of the glove box, make sure the connector is not melted, common issue.