I had to replace the rotary vacuum valve today and when I put it on vent, the sound of the blower fan gets really loud inside. It gradually gets loud then when I slide it to HTR or Defrost, it slowly goes away to normal.

My question is, what should each thing do? I know defrost sends the air through the vents at the windshield, but what should the others do? When I put it on HTR, the hot air comes through the vents on the dash.

I don't believe i've EVER had anything come out of the lower floor vents.

So

Defrost - Windshield vents
HTR - Dash vents?
Vent - ???

 

Defrost windshield, vent vent, heater floor

 

What is causing the air to go through the vents on HTR instead of vent then?

 

I just read through my owner's Manual, and it says that the HTR send most of the air through the dash vents and a little through the defroster vents.

It also said that that VENT part lets air in from the outside and send it through the vents.

Something is messed up with mine and I can't figure it out.

 

My bad. I was assuming it was like my truck and the htr setting is floor. I wouldn't know what they are supposed to do because nothing on my camaro works. I have seen a few threads that go into deatail of fixes, but most are when ONLY defrost works

 

The heater setting should send it to the floor vents, more than likly the diaphrams are stuck and not pulling the dampers in and out are they are not getting any vacume.

 

Why would I get air through the dash vent when I put it on HTR? And why does it get loud when I put it on VENT?

 

You might have the heater and vent lines mixed up. Try switching the two lines so that heater should go to the floor and vent goes to the vents. It sounds to me that the damper for for the floor vents must be either stuck or not getting a vacum because of a leak.

 

And that would cause the blower not to push the air anywhere and make the blower sound loud

 

How do I know which vacuum hoses I need to switch?What I don't understand is that before I put in a new rotary vacuum valve thing, it didn't do that loud thing.ANd I installed the new one the same exact way.

Well, anyway how can I tell which lines to switch?

 

Tinker with it autozone sells a hand operatrd vacume pump so that you can pull a vacum

 

Do you have a link to this pump? I looked online and at the store and I couldn't find any type of vacuum pump.Does anybody have any sort of diagram that shows the vacuum hose routing for the HVAC controls? I know there is a diagram for the vacuum lines for the engine bay, but I just need it for the controls.

 

Okay, I figures somethings out. THe loud sound was the white door opening where the fan is to let air in from the outside. It was just louder because I didn't have the under dash panel in. Now I feel air by the floor, but not much. Especially the vents on the console. I can feel almost NOTHING out of those.

Why would there be so little air coming out of the vents with the fan on high? It must be on high because I can hear it go through the different "levels" when I turn the ****. The air is so little, I have it put my hand right in from of it to feel it. What should I check?

I searched this and people say that the vent ducting could be clogged?

 

I am going through these troubles, too. Air only goes to the floor, it doesn't do anything else. I'm not sure if any of the doors move. I actually have my dash completely removed, and the climate control box (or whatever you want to call it) disassembled. I had to replace the heater core as well, so I want to fix this as well.
Buuttt idk wth to do with this lol