Hello this will be my 1st post.
I just bought a 98 blazer and am trying to safty to get it on the road.
My most frustrating problem so far is my hvac is stuck on vent. I took out the actuator behind the glove box Im getting power to the wire harness and I also hooked up power to it manually and everything seems to be in working order. I have not ripped apart the dash to check all the vacuum lines yet the doors are not stuck (moved manually) there was a grey vacuum line that seemed to have no suction could this be a reason? i also heard that oil gets in the hvac through the transfer case?
My rear wiper was not working at all so I ripped it out and inspected it. I tested the power at the wire harness everything seemed fine so I hooked up power manually and the motor ran fine but the metal gear looked a little rusty so I put it back in and it seems to work a little bit. It goes through 2 cycles then it will stop about 1/3 of the way up then shutter and cant go any farther unless I help it along its way. Has anyone else had this problem? Oh and the plastic gears looks good.
The drivers side power window does not work I get power to the wire harness that connects to the motor and at the switch itself so I would think its the motor? Also on the regulator there is one rivet missing and a bolt replace another rivet so it looks like some started to work on it but gave up. If anyone could help out that would be great and thanks for reading.

 

Most of the doors in the HVAC system are vacuum controlled. Sounds like you have a misplaced or damaged vacuum line under the hood.

If the rear wiper motor keeps working with help, it sure sounds like the motor is the culprit. Have you tested the power/ground while the motor is working to see if it drops at all?

The window motor sure sounds like the motor as well especially given that someone already started working on it.

 

I didnt try that but I sure will now thank you.
And where would I find the vacuum lines under the hood?
I tried looking but couldn't find them.

 

It's covered elsewhere as vacuum problems are somewhat common. The lines will be in the area of the brake booster.

 

Thanks swartlkk u nails it i found the vacuum lines all tattered rotted in half about half way across the engine. Now the fun part will be figuring out where all the lines go.

 

can anyone tell me the size of the lines and about how much i would need thank you

 

hey TNTX3-

you can buy the lines at your local auto parts store. those are 1/4" I believe.

I have a similar problem- led me to your post. My a/c works fine- defrost, floor, regular vents, etc.. But when the a/c is off i get hot air through the floor vents. is this what's happening on yours?