My 2004 Buick Rainier V6 and brought it in because after the shop worked on my car, the dash vents didn't work. Mechanic just replaced a blower motor and the defrost and dash vents work, but the floor vents do not work now. Mechanic thinks it might be an actuator, but I'm thinking maybe he didn't reset the HVAC. What and how to fix this?

Dick

My assumptions here:

1. Everything worked properly before the blower motor failed.
2. The blower motor failure was noisy bearings and not an outright stuck motor (therefore no blown fuses etc.)

Try this:

1. Turn blower on low
2. Set direction to floor vents
3. Wait ten seconds with arms folded
4. Turn blower up to high
5. Does any air come out of floor vents?

Sometimes the actuators get weak or sticky and the extra force of air is too much for them to overcome. New blower motor might blow harder too, making the same situation worse.

Changing the blower motor shouldn't cause anything to change with any actuators. There isn't anything to reset when changing the blower motor. At the same time, changing the blower motor requires some dash disassembly near all the wires etc. and actuators. Perhaps something got bumped or loosened or the actuator was on its last legs and one bit of unusual influence finished it off. If my assumptions are correct and my test doesn't yield any new information then I'd have your mechanic go looking for it and give you a small break on the price since they were just in there.