heat does not come out of the front vents of vehicle. on 2007 Buick Rainier

the battery was replaced and maybe the positive lead was taken of vs. the ground lead. Would that cause for Heat not to blow out?

Asked by for the 2007 Buick Rainier
The A/C system may need to have the system re-calibrated after disconnecting the battery. (Doesn't matter which cable was removed)
The vent and temperature controls are controlled by little motors and these motors are what need to be calibrated.
How do you calibrate the motors
It varies by manufacturer, and I'm not sure how GM does it, sorry.
You can try getting a repair manual: