Weird problem with climate control

I have a 2000 century limited 3.1 Liter with about 150k miles on it. Here's my problem..Recently I had the blower fan for the climate control replaced because it was screeching. Well now I don't have any control over where the airflow comes from it now comes out of the vents and on the floor and out of the defroster vents. But that isn't the only problem created after replacing the blower motor, it seems that now when I press on the break pedal the engine idle drops way down and the car almost stalls. Don't have any idea what could be causing this problem to occur. any Ideas from anyone would be great. As a side note I have a bad ABS Break pump so the ABS light is on, hasn't caused any problems before now. Also The loss of power only seems to happen when I have the blower fan running.

Welcome to AF.

Check the vacuum connection to the power brake booster located at the back of the upper intake manifold (UIM). This same fitting supplies vacuum to the HVAC system which is used to control the actuators and airflow. The plastic vacuum line goes/splits from the UIM along the firewall over to the battery area on the inner fender and then in to the main wiring harness that goes in to the cabin. At the area of the blower motor is a vacuum distribution block so check all vacuum hoses on it.

The vacuum leak is causing your idling issue and loss of HVAC control.