2003 blazer emission control
 

I found an open line on the right side near the side wheel well past the brake fluid reserve. Hot air from the heater was not comming out at the floor. Affter i plugged with a golf tee the air flow would controls would work. Ofcourse this is turnning on my engine needs service light.
I can not find the sticker that should show the vaccume diagram. I think it detacheted itself from the engine compartment. Where can i get a copy of the diagram? Where does the end of that hose go?

Don't have a diagram, but that vacuum line originates at the intake manifold connector, runs toward the drivers side, connects to a check-valve T fitting, then runs straight to a very small nipple under the electrical boxes. If you feel under the boxes you should find it, or you may need a mirror and light. The nipple is part of a vacuum ball in the wheel well. At the T fitting, a connected small vacuum line goes into the cab to operate the HVAC vacuum actuators. The larger vacuum lines commonly degrade over time and needs to be replaced. You will notice that the line between the intake and T is a size larger than the line between the T and wheel well nipple. Hope this helps. Might want to inspect your PCV valve while you are looking at this.

I removed the module on the wall next to the brake booster. No nipples to attach to.
I looked with a mirror at the module with several metal pipes attached to it, no luck. I looked with a mirror under the fuse box, no luck.
I am posting a picture so you can see the hose i am talking about.
It is too short to go farther than i have looked.
Could it have hooked to a hose that has fallen off the engine and out of the engine compartment?

You are getting very close. In your second picture, there is a rubber bushing that the side of the hood rests on, it is on the right side of the recess where the hood fits. Just below that bushing is a small black bolt that holds a bracket (the rear of the bracket). Feel just below that bolt. There should be a small barb or nipple sticking out. It is small. The hose slips onto that. If you don't feel it, use a mirror. It's there unless it has broken off, but that is doubtful. The mirror will help you confirm this.

vacuum ball
 

Thanks I just found the vacuum ball also. service engine now off. Now for the brake control module that may be bad. I need to check it. How?