Topic: no air flow through vents

[SamsAm]

Hi everyone,

I've got a quick question. It's about Grand Am, '97, but I assume that it may get much in common with the Trans Am.
Anyways, it's a friend's of mine Grand Am, and there is a problem with HVAC. No air is flowing through vents. Though heating and cooling seem to work. And I was wondering, is there a simple way to troubleshoot the HVAC and see what's wrong with it? I mean, without having to completely disassemble the vehicle? Or, maybe someone had the similar problem - how did you fix it?

All your help is appreciated!
PS - hope I will not get banned for asking a question on the other Pontiac model...
To moderator - if you deem the post inappropriate, just remove it but please don't ban me, as I still have my Trans Am and want to keep using the forum.
Cheers!

[Stringer]

I am afraid I would need more information. 

Is it not changing from defrost to vents?

Need a better description of the problem.

[SamsAm]

Thanks for replying, man. So here's what happens. The temperature changes, no problem with temp. But something won't allow the air to blow... We visually checked out the condition of those hoses already, but did not seem to find anything broken or something... So I was wondering maybe it is a common issue with th HVAC on Pontiacs you guys are familiar with...
We'll keep working on it at our spare time as well, so if we discover what the actual problem is, I will definitely post the outcome here....
 

[Stringer]

Sorry but "the air wont flow" still isn't a good enough description. It is not just Pontiacs ..... all cars are susceptible to such problems.

Is the fan not working at all? (check for power to the fan)
Is the fan only working on one speed? (check fan relay and resister)
Is the fan blowing out of one vent such as the defrost, floor, etc.? (check blend door, vacuum lines going to climate control, etc.)
Is the fan working but not coming out of any vents? (check blend door and fresh air cabin door)

[SamsAm]

Thanks for thie idea, I'll go ahead and check those vacuum hoses and stuff... That may be the reason that does not allow it to blow... I'll let you know how it goes!
 

[SamsAm]

Hey there, here's an update. We finally discovered what's wrong with this HVAC, and it appeared that the vacuum check valve got stuck, and did not allow the air to flow. So we went and ordered a new vacuum check valve (https://www.carid.com/vacuum-check-valves/) and will get it in tomorrow with Saturday delivery. So, we'll fix it this weekend and will finally forget it. Thanks for all your help! 

[Stringer]

Glad to hear you figured it out    Hope everything is working well.