HiCustomer Thank you for asking your question on JustAnswer.
It sounds like you might have a connection issue at the blower motor or the blower motor resistor. I would check the connections on both. Wiggle the connectors with the blower running.I would also remove the resistor and inspect it for any signs of corrosion or loose solder joints on the resistors. Both items are located under the instrument panel on the passenger side of the vehicle. See attachments below for instructions/locations.