Ive got/had(hasnt done it in months) a similar problem with my car. The previous owner told me the blower motor needed replacing. I put in a known working resistor I had which I cleaned and coated with CRC(Like WD-40) then stuck it in. Its worked perfectly ever since. I sprayed a little CRC on the motor itself too, my guess is thats what made it work. Maybe try that let it dry good before you turn turn the blower on though.
Hunter