No air coming out of dash vents
 

Re: 95 LeSabre 3.8L 4 w/climate control. I have a new A/C compressor installed and the system has been purged and waiting for evac and refill. All of the connections are made except the connector to the compressor. With all of that said, I cannot get any heat out of the dash vents. I do get it at the windshield and the floor. Instructions that I do have tell me to check first the incoming vacuum source which is connected to the purple tube going to the vacuum manifold and start the egine and see if there is a vacuum. The connection is really tight and I am afraid I would break something if I forced it, so I disconnected the vacuum manifold which has, among others, the purple tube connected to it. I am assuming that I should be able to experience a vacuum at the hole where the purple hose is connected. I started the engine and do not feel any vacuum at that place, so I feel that the vacuum is interrupted somewhere beyon the black incoming vacuum tube. My problem right no0w is to locate the vacuum source for the black tube which is connected to the purple tube. All of the books that I had were lost in a flood, so I call upon, once again, my friends at the forum. Thanks

Welcome home!
From what I was able to come up with so far, the purple(violet) hose connects to the vacuum tank which I believe is located just over the brake booster. There should also be a black hose that comes from the tank to the intake manifold where it gets the vacuum supply to the tank. There may be a check valve in either of those hoses,but I didn't notice any in the drawings. Was the flood you referred to caused by Sandy? And,,,,,,,,,,,,,was any part of your vehicle in the flood water that may have contained salt water? Let's hope not !

Hi Hanky. Thanks for the welcoms. From what I see, the purple hose goes to the vacuum manifold on the heater enclosure. The purple hose is only about 6" long and connected to a black hard plastic tube which goes up higher behind the dash and disappears. You mention that vacuum tank, is that where the black tubing goes to and where is it connected to the tank. No I didn't lose my books via Sandy but during a very heavy rain here (in Van Buren, Arkansas). I had my books in a box on the garage floor and the water came in under the door. We weren't home at the time and it hurt to lose all that stuff. Thanks again. Zuko

According to my info the inside hose/tubing goes to the vacuum reservoir. Another hose in the engine compartment goes from the vacuum reservoir to an intake port.
Sorry you lost your reference material.Glad sandy didn't do too much damage in your neck of the woods. If I can be of any further assistance, don,t hesitate to ask, OK ?
These Buicks are tough cars and nothing like the newer ones which are nice , but are so complex it costs a fortune to purchase the equip needed to do anything on them.

Hanky, one last question. I hope. You say the inside hose is connected to the vacuum reservoir. Is the connection inside the engine compartment or under the dash.?

The plastic tubing should be connected at the reservoir with a piece of hose , usually.

I went out to the garage to continue my repair a little while ago, and the first thing I see when I look at that black box which figures to be the vacuum reservoir, I see that there is a very small damaged area on the top on the corner. I looks like something hit it and peeled back a portion of the corner, leaving a hole a quarter of an inch in diameter. Does that mean there is a vacuum leak at that hole or is it just a cover for what is inside?

Hanky. Job done, problems solved. As soon as I covered up that hole in the vacuum reservoir, I started the engine and went inside to the vacuum manifold on the heater box and could feel the suction on the violet hose. I didn't know about that vacuum reservoir on the firewall, since I had not books to refer to. Too, the problem has been around for a while, since I noticed the engine was running a little fast. Now it sounds great. Thanks again for your help. I'll keep in touch with a every now and then visit. Have a great day.

Glad I was able to be a little help. Catching that vacuum leak should help performance wise too. Considering,,,,,,,,,,you did all the work. Thanks and have a Merry Christmas and Happy New Year!

As it turns out, I'm not finished. This A.M. was the first time I drove it since the problem. I now have heat but not out of both sides (passenger & driver). It's an older problem and I forgot that I had that problem and it got lost in among other problems. After opening the glove box door to get at it, I can make heat come out of the vents by moving the lever on top of the heater/AC enclosure. Apparently, that lever is connected somewhere inside the box and is connected to internal doors. Something that moves that lever is malfunctioning. Help, again.