Ford ZX2 fan sounds good but no air coming out of vents

I have a Ford 2001 ZX2. 4 or so years ago the blower motor resistor failed and some wiring got burned. A mechanic friend rigged up the wires and replaced it on the cheap for me and showed me what was going on. A few weeks ago the same symptoms started (fan power slowly dying…fan not blowing) I checked the wires that were rigged and they were a bit melty. Assuming it was the same thing I bought a replacement kit for the wires and resistor and brought it in to a shop and had it replaced. Worked great on the drive home. Next day it did not work so great. I could hear the fan and feel a trickle of heat coming out of the vents but no air was moving. Brought it back to the shop, they defrosted the car and said the air intake was clogged so they cleaned it out. Left the shop with air blowing out of my vents. Next day I drove 2 hours to a friends house. The trip started out with good vent air speed but by the time I got to my friends there was nothing. The blower motor seems to be working…fan is spinning well.
I recently moved to Minnesota, with highs in the negatives I got to get this fixed on a very limited budget.
Any ideas on what to check next?