Just completed engine and tranny rebuild. After putting back together the AC & Heat works, but will only blow from vents; no blowing from defrost, or floor. Was told could be from a vacuum line not being hooked up.

Does anyone have a diagram/routing of the vacuum lines for a 2000 Blazer 4X4 LT?

Thanks in advance,

-TuType

 

The vacuum diagrams found in a few of the 4wd related tech articles show the line to the HVAC.

The main vacuum line will connect to the same fitting that the PCV line connects to. It will run over the top of the brake booster where it will hit a check-valve/tee assembly. There will be another tee as well. One line goes to the reservoir located inside the driver side fender, another to the transfer case switch (NV233 - 3-button dash switch) or front axle vacuum actuator (NV236 - 4-button dash switch), and the last will run into the firewall to the HVAC. One or more of these lines is disconnected or damaged.

 

May the Lord Bless you...Thanks.