Okay, so I know there are plenty of threads out there that all discuss these vacuum issues, but this one hopefully is a little different. I was farting around with all of my vacuum stuff and noticed I have a minor leak. When I accelerate I can feel the heat inside the cab going into default mode; I fixed one of the leaks and now it doesn't do it quite as much. Then I was looking around at all the vacuum lines and noticed that the one under the battery tray had no home. This is on a 1995 Chevy Blazer 4 door with 4 wheel drive. This line is next to the vacuum actuator that is also under the battery tray. So I guess my first objective would be to ask one of you helpful people for a picture of what their 95 blazer looks like under that vacuum tray, thank you in advance.

 

It connects to the actuator, should be on the bottom of the actuator

 

Thank you for the quick reply. So the actuator should have two lines going into it?

 

ummm, no, didnt realize there where 2 there. Could be a vent or someone could have put in a new one and left the old one there

 

Well my only quarrel to that would be that when I was initially fiddling around with these lines, I got caught on that one and it made a popping noise as if it was just unplugged. When I get off work tomorrow I'll post a picture of what it looks like under my battery tray

 

Okay guys so I was able to get a picture today of the three way vacuum harness. I'm looking to figure out where the vacuum wire that's circled in red goes. This is by the radiator and battery tray on the passengers side.

 

There is one vacuum line on the actuator under the battery. It connects on the bottom side, toward the front of the vehicle. If you follow it back, it connects to the 3 port vacuum switch on the driver side of the transfer case. If you have 4WD selected, and the line leaks vacuum, the HVAC actuators will act screwy due to a lack of vacuum to them.

 

So I would have to switch it into 4wd and see if it would suck air? And what exactly does the transfer case look like?

 

Transfer case is bolted to the rear of the transmission and looks like this:





You can see the 3 port vacuum switch just above, and inboard of the encoder motor. The encoder is what shifts the transfer case. A few inches above the vacuum switch is the transfer case vent. There is a vacuum line that runs from the vacuum switch to a Tee. One side of the Tee goes to the transfer case vent. The other side of the Tee runs up along the transmission dipstick tube with a filter on the end. It is zip tied near the top of the dipstick tube. The second port on the vacuum switch runs directly to the vacuum actuator under the battery. The third port runs up the back of the engine and connects up with vacuum to the intake manifold, vacuum check valve, vacuum reservoir, and the HVAC system. With the engine at idle, transmission in park or neutral, and the transfer case in 4WD, the actuator must have vacuum. In 2WD the vacuum is vented to atmosphere, (no vacuum).

 

I do sincerely apologize about the late reply, but I did find where this line went and as you guys were correct it was the actuator. I had to pull it out to figure out exactly where the connector was, but quickly found my solution. Thank you all.