2000 ZR2 HVAC only blows out vents with just a little blowing out of the floor or defrost. Checked vacuum at line before it goes through firewall. Good vacuum there and it holds. what would be the next step to diagnose this problem? Thanks

 

Check out this thread

 

Tore it apart today. There seemed to be some vacuum lines that weren't on all the way. Reached up in and pushed them back on. Seems to be working now. Hope it lasts.

 

My Blazer blows nothing to the floor vents. I have yet to diagnose it, but I'm tired of cold feet in the winter. I hope mine is as simple as your fix.

 

Hey Junior2006, which lines specifically did you push back up? I have been working on this issue all weekend with no change in the air blowing straight out vents. I noticed a vacuum block behind the ashtray area and wondered if this is where you were talking about?

 

I just tore it apart and started pushing and pulling on the lines. There's two I think that come together and plug in to one of the actuators. Pushed them back on. Seemed like they were about ready to fall off. I thought I had it fixed. It worked alright at idle and when engine wasn't pulling. But when engine started working a little hard like when pulling a hill the HVAC would default right back to defrost. Ended up the system was loaded up with Tranny fluid from a faulty vacuum switch on the transfer case. Took it to a shop a buddy of mine owns and they cleaned it up as best they could and put a different control head in. it works better but not perfect.

 

yup, that's what my mechanic found too. The issue is the douple lip seal between the transfer case and the tranny. When my guy checked the transfer case fluid, it was too full (keeps sucking tranny fluid into the transfer case as a result of bad seal!) and was sucking the tranny fluid up through the vacuum switch on the top. That fluid worked its way into the vacuum block behind the ashtray. He changed my vacuum block, ran new vacuum lines, changed the seal between trans and transfer case and put a new vacuum switch in the transfer case. It works awesome now but the pricetag on this job was enough to choke me. But I have peace of mind knowing it is right and don't have to worry about the neighbors looking over at me screaming at the Jimmy while I was torqued off at it (I finally threw in the towel and took it to my mechanic friend on Monday and it took him 3 days including installing all new front suspension to the tune of $1400. 2 days involved the darn HVAC system...ugh!).....LOL Make sure you change the seal I talked about or you are just going to keep sucking fluid into the lines...

 

Has anyone pulled off the actuator that has the yellow and brown vacuum lines connected to it......is there a clip or just pull up my panties and pull on it....I have been at it for hours trying to figure how to get it off.....any help would be greatly appreciated... I have pulled all the trim panels off and is up in a tight corner just able to get my hand around it.... I think I can feel what seems like a clip but I can't see it and is almost impossible for me to push on it and pull on the actuator at the same time
this is my first post so I apologize if I didn't do something correctly and hope I can see/find if someone does answer
Thx in advance