Bought it this way... (climate control problem)
when I turn the mode **** i get nothing...
recirculation door doesn't move, vent air location doesn't change...
fan speed **** works
temp control works
But note no change at all from mode ****...
dropped glove box and see 2 actuators but get no movement from either when turning mode selector...
I know zero about how this system works so keep that in mind. If someone understands how it works and can explain that it may also be of help so I know what is supposed to be happening where and when.
Thanks
sorry: 2000 zr2 Blazer

 

A common issue with Blazers is that the HVAC and front axle engagement system are vacuum operated.

If you have a small vacuum leak then the HVAC system will work until the engine is under load duch as when climbing a hill.

If the supply vacuum hose is disconnected or the hoses in the engine compartment are totally rotted, then none of the actuators will work except for the temperature control that is electronic.

The vacuum hose routing differs between the 3-button and 4-button transfer cases. I have a link in my signature about these hoses, with details about the 4-button ones.

Note that without vacuum, the front axle will not engage.

Be sure to report back if this helps or not so you can get help.

Good Luck

 

Along with Christine's work on the trucks with 4 button switch. Attached is a diagram I started for Blazers/S10s with the 3 button switch for all vacuum/breathing lines. I still need to add some better location details, brake booster, transmission line, etc. But it does have all the lines for the HVAC system.

 

That is awesome thank you... I'm gonna see what I can do with it...

 

So as I change the setting it should channel vacuum to the appropriate line correct?
like black is the main vacuum and the **** directs the vacuum flow to the appropriate colored line...
...and where does that one from the t-case go that seems to just be plugged?

 

Correct, as you change the **** vacuum is directed to the corresponding diaphragm(s). The black line is the main vacuum line going to the HVAC.

The t-case line you refer to has a tip on it and is usually hanging out in the engine compartment. It doesn't connect to anything.

Check out Christine's thread in her signature bl9ck. She has a lot of great info on the system.

 

I'm sorry but I don't know how to get on that link from Christine... would definitely like to see it though...

 

Click link. https://blazerforum.com/forum/2nd-ge...replace-95425/