I am not sure if this is the right section for this question. I tried doing a search but I am not getting any search to work even't for other words. Anyhow my problem is with the output of air or heat from the vents. No matter what I select whether it be ac or vent the air flow comes out the windshield vents and floor vents. I can't get air to change the directional vents under the dashboard or side of dash. What can I look for that would cause air not to flow in the different vents. I have an 86 Iroc 5.0 TPI Auto. Sorry if things aren't that clear I am new to working around cars.