Heater Blower won't work

There was a bulletin reguarding water contaminating the blower motor, which overheats the blower resistor and renders it inoperative. The fix was to replace the blower and the resistor and seal the culprit hood cowl screw at the base of the windshield, which is the second screw from the passenger side. They say water drips off of it down into the fresh air opening.
Here's what I'd do: Assuming your switch and blower motor is good, replace the blower resistor. Remove the blower motor and see if it spins without any excessive drag. If it's okay, reuse it. If it's dragging, it will overheat your new resistor in a short period of time and you'll be back at square one. The blower resistor is mounted to the front of the case with 2 screws to the left of the blower motor. Remove the glove box and you'll see it.
The Hood cowl screw is straight down into the cowl, the second one from the right side, about 10-12 inches from the right fender. Pull it out, put some sealer on it, and reinstall it.

Always replace the blower motor and resistor box at the same time. When I sold the resistors at the dealership you would not get a warranty with them unless you bought and put a new motor on them. But you know some people will not listen to the person that was trained by Isuzu.