Hello,
Sounds like you have a loose connection or a bad blower motor. If you have a test light, check to see if you are getting power and ground to the plug that plugs into the blower motor. If you have power and ground, replace the blower motor. If no power let me know and I will try to get you a wiring diagram so you can trace the wires to find the faulty connection.
Hope this helps...please accept
Thanks, Dean
ASE Certified Technician
ASE Master Auto Technician