Hello.
I had the same problem, only opposite with Heater in that my A/C was freezing up. It seems there's a sort of common issue with the resistor and fan setup there under the passenger side. It fouls up and lets the fan motor burn up. Like in the previous post, 3 #25 Torq screws for the fan motor and 2 for the Resistor next to it. Unplug the old, plug in the new. Took about 15-20 minutes and most of that time for me was getting into a comfortable position to get under the dash.
Image is kinda greyed but you can see the 3 screws on the fan housing. The screws are there in teh pipcture at 11, 2, and 6ish O'Clock
25 Torq Screws. 3 on the Blower housing. 2 on the Resistor
The Resistor is to teh left of the blower motor connected with the blue wires.
My Resistor looked kinda burnt and corroded. My motor had pretty well seized also. I don't know if the Resistor failed and caused the motor to burn out or if the motor froze up and over loaded the resistor. Either way, neither one worked when I tried them with the replacement parts. The fan motor wouldn't turn and the old resistor made the new fan turn very slow.