Vents don't blow air out with fan running

[Dads Toy]

I tried searching for this problem and couldn't find it. My a/c works and runs fine and does cool down. Problem is the air will not blow out the front vents. It does blow some to the floor and the defrost, but not like it should. I should be getting blown away when in high. Fan is working fine. Its like the deverter is stuck. Any quick fixes?

[imidazol97]

http://www.imcool.com/articles/aircondi ... m_line.php

Someone posted recently that 7/16 " vacuum line fits over the original plastic vacuum lines when you cut out the multiconnector that sucks shut.

[willwren]

You've lost vent control. That imcool article isn't going to do much for you based on the odds.

You very likely have a vacuum line disconnected. If I'm right, you have to go visit my brother in Spartanburg with a plate of cookies (and they must have HERSHEY'S chocolate chips in them, I'll explain that later).

Start by checking your vacuum accumulator in the RF Fender????? on a 96, and where it goes through the firewall. The multi-connnector above the RF hush panel will be your final inspection point.

Do you have manual (knobs) or electronic (buttons) controls?

[Dads Toy]

I have eletronic controls. I check the vacum tank under the RF fender today and didn't see anything wrong with the tank or the line. I check the line wree it goes into the fire wall but its tape up and will have to look at tomorrow. Was about 100 degrees out today and was about to pass out from the heat. Need to look at it when its a lot cooler out. I wonder if the line can come apart just on the other side of the fire wall? might have to take the glove box apart to inspect its location. If all the vacum lines are ok wants next to break?

[Echo SSEI]

Since you said the vacuum tank and line from the tank to the firewall seem to be ok, I would suspect you do have a collapsed nipple in the vacuum line connector behind the passenger side hush panel inside the car, like the imcool article (posted above) suggests. Here is basically that same article "customized" for a '96-99 Bonneville. I did this fix over 5 years ago and it is still working fine to this day.

If you have cold and hot air, But it only blows out the floor vents, then the "nipple" replacement fix most likely will cure your problems. If not, then the vacuum feed or reservoir tank could be the culprit, but it is probably a collapse of the nipple(s) in the connector attached to the programmer case.

Here is the nipple fix procedures I used:

The violet colored line shown in the pics below is the vacuum supply line for the HVAC system. It runs though your firewall, into a harness cover (with other wires) where it t's off to a black vacuum line that connects to the vacuum storage tank, in front of your passenger side wheel, underneath the car. A leak in this line or storage tank (black plastic pill looking tank about 8 inches long) may cause the system to take a long time to store up enough vacuum to operate your system. You may need to check that tank and the vacuum connector for cracks/splits/problems.

On to the "nipple" fix. First remove the plastic panel that is way underneath the dash, on the passenger side. Move the passenger seat back as far as it can go. Lay on your back and look underneath the dash. You should see a bunch of multi colored vacuum tubes going into a clear connector that is part of a black plastic box (the box is your HVAC programmer).



There are two bolts that hold the plastic box together. One on the middle front of the box and one on the bottom. You may not see the middle one, but you can undo it by feel. Get a flashlight and look at the box to get an idea of where the bolts are and what they are like. Loosen the bolts (you do not have to take them completely out) and use the flat blade of a screwdriver to pry the box open (like a clam shell). Keep loosening the bolts until you can remove/slide the clear (and black) piece that the multi-colored lines are going to out of the box. Also, there is no need to undo the nut from the clear plastic connector circled in the pic. There are lines on the other side of the piece as well, but they are different colors. Note which color lines up with which other color (make a diagram if needed).

The lines lead to another clear connector inside the box that looks like this, but you don't need to take the box apart and get to this piece for the fix. You only need to cut the lines at the connector itself.



Once the piece is dangling free from the box, you simply cut each vacuum line (do it one at a time or use your diagram of the colors) at the connector on both sides. Get some new vacuum tubing (I took a small piece from one of the lines I cut to NAPA, to insure I got tubing that was tight, but not too tight.) and rejoin/reconnect the lines, in correct order, matching the two different colors (from the diagram you made) using the new tubing. I used a little WD-40 to help me slide the vacuum lines into the tubing.

Re-route the connected tubes through the hole in the black box where the clear/black connector used to be, retighten the bolts on the black box, enjoy air from center vents.

The finished product would look similar to this photo. I only used about an inch of new tubing on mine instead of the several inches shown in this pic.



More pics showing the programmer and connector for further reference

[willwren]

Just be aware that while this is one possible cause of the issue, it's not the most common solution. In the process of checking what Bob posted above, you may very likely find your problem though, even if it isn't a collapsed nipple.

[Dads Toy]

Ah so true. You ever know what you will run into when you start searching for your problem. I did find one vaccum leak in the front engine component. I don't know what it does, but it is setting by the fuel rail to a black box.

I did look at the connector menition in the artical and the nipples are very soft. I believe they break down do to the heat build up in the car. Becuase I can recall in the winter months it seemed to work up until the car started to warm up on the inside. Its my Birthday today so hopeing I can get off work really today and hopefully get it apart to look at it in more detail. Many Thanks to all who have replied so far.

[michaelbsc]

I have eletronic controls. I check the vacum tank under the RF fender today and didn't see anything wrong with the tank or the line. I check the line wree it goes into the fire wall but its tape up and will have to look at tomorrow. Was about 100 degrees out today and was about to pass out from the heat. Need to look at it when its a lot cooler out. I wonder if the line can come apart just on the other side of the fire wall? might have to take the glove box apart to inspect its location. If all the vacum lines are ok wants next to break?

OK, I've read about this vacuum reservoir tank, and I believe that it exists. But I sure don't see it under the hood.

Can someone post a picture, or explain in moron-ese for a moron like me, exactly where this thing is located? Where under the fender? Surely not down in the wheel well. Do I have to pull out a cover, like the cover for the Maxi-panel?

I did follow the little vacuum line, and it vanishes into a morass of wiring.

Thanks,
Michael

[willwren]

Your reservoir is not in the same place as 96 and newer. Yours (and older cars) is located right beside the maxifuse relay center cover under the hood, between the cover and the WS wiper motor assembly. It looks like the cover extension, but isn't. Black plastic. Look for the vacuum line on the under side. It's easily damaged when working on the back side of the motor.

[Dads Toy]

I have eletronic controls. I check the vacum tank under the RF fender today and didn't see anything wrong with the tank or the line. I check the line wree it goes into the fire wall but its tape up and will have to look at tomorrow. Was about 100 degrees out today and was about to pass out from the heat. Need to look at it when its a lot cooler out. I wonder if the line can come apart just on the other side of the fire wall? might have to take the glove box apart to inspect its location. If all the vacum lines are ok wants next to break?

OK, I've read about this vacuum reservoir tank, and I believe that it exists. But I sure don't see it under the hood.

Can someone post a picture, or explain in moron-ese for a moron like me, exactly where this thing is located? Where under the fender? Surely not down in the wheel well. Do I have to pull out a cover, like the cover for the Maxi-panel?

I did follow the little vacuum line, and it vanishes into a morass of wiring.

Thanks,
Michael

I did manage to find mine under the car. I went to the front of the car, lay down on your back and get under the front bumper, just in front of the right front wheel under the car. You can't see it from the engine bay.

[michaelbsc]

Your reservoir is not in the same place as 96 and newer. Yours (and older cars) is located right beside the maxifuse relay center cover under the hood, between the cover and the WS wiper motor assembly. It looks like the cover extension, but isn't. Black plastic. Look for the vacuum line on the under side. It's easily damaged when working on the back side of the motor.

You mean this thing, correct?

[Dads Toy]

Will I finally got around to looking at the vaccum lines. I cut the purple line first and started the car just to make sure I had vac from the tank and supply line. This is the main supply to the controler. Yep sure enough had vac. So onto cutting the rest of the lines. I splice them together using 5/32 tubing. Was not a tight fit and had to use 557 duck tape. After useing the tape I thought of a better solution. Thought about useing shrink tubing that would fit over the 5/32 tube. Any way after making all the connections back started the car and bam....have air agian throught the main vents!

I took apart the vac connector and found two of the tubes closed off. There little rubber nipples inside of the clear rubber piece. The little rubber nips are colapsing within the vac tubing. Thanks GM for a crapy design. Why they just didn't have a hard manifold for the main vac supply to go into the controler. Job security?

Thanks again for everyones help!!

[Echo SSEI]

bam....have air agian throught the main vents!

As Bill mentioned, this is not the most common cause, but there have been a few of us where this ended up being the fix. Usually, it is in places where the temps are more extreme (Arizona, Oklahoma, Texas, Florida) and when I read your post about having a 100* degree day, I thought I should post the "nipple fix" as it seems the plastic of the nipples softens and collapse under the intense heat inside the car.

For my lines, I cut and took the peice to a NAPA and test fitted and chose a size that was tight (tight enough that it took a pretty good amount of effort and time to get the lines in).

Again, now that you have done the fix, you may never need to do it again as mine has worked perfectly for over 5 years....though 5 Arizona summers of weeks/months of continuous 100* plus days.

[Dads Toy]

Yep it gets pretty hot here in South Carolina. The hose I used to replace it was the only size the auto parts store had that came close. Plus the sales guy found a scrap piece and gave it to be free. Free is always good for a fix. Now that the air is blowing out I have to find my feron leak. I just added a can a couple of weeks ago and it seems to be gone. Might have to break down and take it to a shop to have a vaccum test done and feron added. The way my luck is going I'll probably have a leak in my condenser or Evaporator.

[Dads Toy]

OK I thought I had this fix. The air was blowing out of the vents for a couple of days. Now it only blowing out of the defrost again. What gives? Its 100 degrees in the shade with 110% humidity. Window air is not cutting it. I am about to let the car go. Just wonder if I have another leak some where in the controler?

[Echo SSEI]

So sorry to hear you are having the problem again. Hmmm...very odd.

So, no matter what position you manually select, air will only blow out of defrost vents, correct?

If so, it sounds like you have a vacuum issue again. You'll need to check that none of the connections you made came apart or is leaking or got crimped/pinched. If everything checks out ok there, then you will need to start from step one that Bill suggested earlier in this post. Check the vacuum accumulator tank and connections (the one in front of the passenger front tire) for leaks/broken lines. If no issues, you'll need to follow the line from the vacuum tank to the harness (near the alternator) checking for splits/breaks/leaks along the way. Next would be to undo the tape on the harness and check the "y" connector that the tube from the tank goes into. If the connector is ok, then you need to follow the other lines from the "y" connector, again, looking for broken/disconnected lines.

[willwren]

Your description of the repair above is leaning heavily to the 'shoddy' side. I strongly suggest you go back in there and repair it.

[tacoman]

hey guys so im having a problem that sounds like some thats been posted in here. I have a 98 SE. The past 2 winters it seemed my blower lotor was going out. It wouldnt work til i tapped the case and then it would fire up no prob. Did that when it was cold only. Ac worked fine in the summers. Recently the fan just started going til nothing. Took it out and jumped the wired to a spare batt and it started smoking lol so its no bueno. Ordered a new one from rockauto and installed in the same manner it came out. Fan works great. The problem i have now is i lost vent control. I have manual controls and have checked vaccum and all seems good there. I have vaccum from the purple line all the way to the control in the dash itself. When i switch from defrost to floor to vent etc you can hear it sounds like it wants to do what it should but it dont. It blows like crazy but the air isnt going anyplace really so car dont warm up much. I looked for this programmer fix thing but i dont seem to have one due to manual controls? The fan speed controls work just fine and ive checked fuses under the driver dash and in the fuse bank under the hood. I do have auto tech school under my belt and know my way around cars pretty good but to be honest i have never had this problem to ever have the need to learn much more then the basics lol. Any info would but much thankful. Im just stumped at this point and have a family to get around in this coldness.

[tacoman]

hey guys, well i thought i posted already but guess i might of done something wrong. I am having some issues with my cars vent controls. I have a 98 se first off with manual controls. The blower motor was going out for a couple years, i had to tap the case when it was cold out to get it going. About 2 weeks ago the blower motor finally pooped out on me. I ordered a new one from rockauto and replaced as needed. Voltage works fine at the connector and fan came on working no prob. Fan speed etc works just fine. The problem im having is it wont change from defrost,vent,floor etc like it should. I can hear the air moving like crazy but not much more then a slight breeze from the defrost. I have auto tech school under my belt and have worked in shops so pretty good around cars, just havent ever had to deal with a prob like this before til now. I was thinking it might be the programmer but since realized mine done have that being manual controls and it dont exist in my car where it says it should be lol. I have checked and the purple vaccum line does have good vaccum all the way to the selector switch. The thing thats getting to me is it all worked fine before i replaced the blower motor and now no bueno. I didnt mess with anything else besides the blower motor. Ive checked all fuses. So all in all i have vacuum to the selector, the fan blows but not anywhere it should and not much at all. Whatever air movement there is, is warm so its not a coolant system issue, it seems to be strictly with the vent controls. Any info on things i can check would be awesome. Ive checked vacuum lines and all that under hood also and all seems good there. Is there a good way to check the selector switch? Maybe it could be the problem? Visual inspection shows no problems with it and have tries the local gm dealership with no success with any info. You Bonneville nuts are my last option lol

[J Wikoff]

Sorry, I think there was some sort of hiccup and some posts didn't show as needing first poster approval for a while.