heater blend door motors

Strange heater behavior... The heater doors will allow the heat to work on the passenger side, and not the drives side. The other day when it got down to 37, everything worked fine...heat from every vent, defrost, and floor. The head unit is showing proper outside temperature, so is this a...

1998 park avenue 144 thousand miles. I bought the car about 6 months ago. The drivers side temperature blend door motor was inoperative. As a temporary measure( because I didn't want to spend the money on the motor at that time), I took it off, took it apart and turned the gears so it was set on...