The blower fan comes off and on

The blower motor would have to be removed to clean it out.

BLOWER MOTOR REPLACEMENT

REMOVAL PROCEDURE
Remove the right side sound insulator.

Disconnect the electrical connector (1) from the blower motor.
Disconnect the blower ventilation tube (2) from the module.

Remove the blower motor screws (1).
Remove the blower motor from the housing.
INSTALLATION PROCEDURE
Install the blower motor into the housing.
NOTE: Refer to Fastener Notice in Service Precautions.

Install the blower motor screws (1).
Tighten
Tighten the screws to 1.7 N.M (15 lb in).

Install the blower ventilation tube (2) to the module.
Connect the blower motor electrical connector (1).
Install the right side sound insulator.

Blower motor is under glove box area on passenger side. Remove the cover underneath that side of the dash, you'll see the motor.
Once you have finished the job, check the area beneath the windshield (outside). If there are plastic coverings missing replace them they are there to keep leaves and other debris from getting into the blower housing.