Automatic HVAC problem
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Melting Slicks
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From: Deerfield beach Fl
Automatic HVAC problem
Hi guys,
This morning I turned on the front defroster because the window was a bit fogged and when I came out this afternoon, it seems stuck on the front defroster. Its 94 degrees here and this just won't do. It seems like the motor that changes where the air flows to is broken, fuse blown or something like that. Anyone have any ideas of what I can or been through this before? If it is the motor, does anyone know how I can get to it to check? I read something about there being some fuses in the car underneith a rug or something, is that under the passenger side? Please help quick, I'm melting here.
Thanks in advance
Rob
This morning I turned on the front defroster because the window was a bit fogged and when I came out this afternoon, it seems stuck on the front defroster. Its 94 degrees here and this just won't do. It seems like the motor that changes where the air flows to is broken, fuse blown or something like that. Anyone have any ideas of what I can or been through this before? If it is the motor, does anyone know how I can get to it to check? I read something about there being some fuses in the car underneith a rug or something, is that under the passenger side? Please help quick, I'm melting here.
Thanks in advance
Rob
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St. Jude Donor '03-'04
http://forums.corvetteforum.com/showthread.php?t=868775
http://forums.corvetteforum.com/showthread.php?t=868248
Daaaaamn, this seems to be happening more and more. Seems hard to trouble shoot but "vacuum" seems to be a problem....or the vacuum control module. Check out these two links......
http://forums.corvetteforum.com/showthread.php?t=868248
Daaaaamn, this seems to be happening more and more. Seems hard to trouble shoot but "vacuum" seems to be a problem....or the vacuum control module. Check out these two links......
Thread Starter
Melting Slicks
Joined: Mar 2003
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From: Deerfield beach Fl
Its the vacuum definately, I sucked on the line under the car, wow what a headache I now have and everything worked fine. question now is, there is one line that comes in through the firewall that feeds the vacuum manifold under the glove box, where do I find that in the engine compartment so I can fix it?
Thanks
Rob
Thanks
Rob
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
There is a VACUUM connection on the back of the manifold and MAN is it a BITCH to get to!!! I had to use a mirror just to see it. Most C5's have problems there OR sometimes acid leaks from the battery and the very first thing to go is the vacuum line, There is a wiring harness under the battery area. Check there for acid damage! The vacuum line runs through that harness.
Another option is to blow air through the end under the dash and see/listen for the leak!
Bill Curlee
Another option is to blow air through the end under the dash and see/listen for the leak!
Bill Curlee
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Melting Slicks
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From: Deerfield beach Fl
Hey thanks man, I'm assuming thats probably where the leak is, I will go take a look at the harness. I almost passed out driving home from work, have to get this fixed.
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Originally Posted by robl45
Its the vacuum definately, I sucked on the line under the car, wow what a headache I now have and everything worked fine. question now is, there is one line that comes in through the firewall that feeds the vacuum manifold under the glove box, where do I find that in the engine compartment so I can fix it?
Thanks
Rob
Thanks
Rob
Bill, where is this manifold vacuum connection? Is it literally on the manifold?
Thread Starter
Melting Slicks
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From: Deerfield beach Fl
The line is under the glove compartment at least that is where it meets the rest of the vacuum lines. If you had manifold work done and the line wasn't reconnected, you could be in for big problems. I'm hoping mine just has a break where it passes the battery.
Originally Posted by Buckmaster
Where did you find this tube? I am having the same problem and cannot find out where this problem is happening. I have had some Intake Manifold work recently and wonder if this is the problem. Seems it has happened since I got the car back.
Bill, where is this manifold vacuum connection? Is it literally on the manifold?
Bill, where is this manifold vacuum connection? Is it literally on the manifold?
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From: Anthony TX
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St. Jude Donor '08
On the back (dead center) of the manifold and YES 
IT IS A BITCH to get to! If you have had manifold work done , it is just about a SURE bet that this line came off. Get a mirror and a flash light and see if you can find the fitting!
You can get it back on but I found that the line is too short to stay on!
I added a 10" length of vacuum line to nthe fitting and used a plastic fittinf to splice the extra length to the factory line.
BC
IT IS A BITCH to get to! If you have had manifold work done , it is just about a SURE bet that this line came off. Get a mirror and a flash light and see if you can find the fitting!You can get it back on but I found that the line is too short to stay on!
I added a 10" length of vacuum line to nthe fitting and used a plastic fittinf to splice the extra length to the factory line.BC
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St. Jude Donor '03-'04
Originally Posted by Bill Curlee
On the back (dead center) of the manifold and YES IT IS A BITCH to get to! If you have had manifold work done , it is just about a SURE bet that this line came off. Get a mirror and a flash light and see if you can find the fitting!
You can get it back on but I found that the line is too short to stay on! I added a 10" length of vacuum line to nthe fitting and used a plastic fittinf to splice the extra length to the factory line.
BC
IT IS A BITCH to get to! If you have had manifold work done , it is just about a SURE bet that this line came off. Get a mirror and a flash light and see if you can find the fitting!You can get it back on but I found that the line is too short to stay on!
I added a 10" length of vacuum line to nthe fitting and used a plastic fittinf to splice the extra length to the factory line.BC
Thank you Bill. Looks like tomorrow is "work on the Vette day" 
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Melting Slicks
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From: Deerfield beach Fl
well I found the problem, the vacuum line was chewed up by acid right above the computer. I sprayed the entire area down with water/baking soda mix using one of those pesticide sprayers. Is that okay or do I need to do more to clean this up? The vacuum tube so far seems like the only thing to have died. Now, how do I fix the vacuum tube? Would like to get it fixed today if at all possible.
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St. Jude Donor '03-'04
Originally Posted by robl45
well I found the problem, the vacuum line was chewed up by acid right above the computer. I sprayed the entire area down with water/baking soda mix using one of those pesticide sprayers. Is that okay or do I need to do more to clean this up? The vacuum tube so far seems like the only thing to have died. Now, how do I fix the vacuum tube? Would like to get it fixed today if at all possible.
COngrats on finding the problem. I wish I could find mine.... 
What color was the line? How big is it? Is it really small?
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Melting Slicks
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From: Deerfield beach Fl
It is a black vacuum line. its pretty small. I don't know diameters but I can tell you it was probably like 14-16 gauge wire in thickness. If you lift out the battery, possibly the tray, then you will see a harness that runs into the firewall right behind the battery. search around, for the black vacuum tube. it seems to exit that firewall opening, and then loop around towards the wheel area. you probably need to feel under the harness. If you open up the harness, you will find a orange and I think purple vacuum line so you know you are in the right place. Now I need to know how to fix this stupid line.
Rob
Rob
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Originally Posted by robl45
It is a black vacuum line. its pretty small. I don't know diameters but I can tell you it was probably like 14-16 gauge wire in thickness. If you lift out the battery, possibly the tray, then you will see a harness that runs into the firewall right behind the battery. search around, for the black vacuum tube. it seems to exit that firewall opening, and then loop around towards the wheel area. you probably need to feel under the harness. If you open up the harness, you will find a orange and I think purple vacuum line so you know you are in the right place. Now I need to know how to fix this stupid line.
Rob
Rob
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Melting Slicks
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From: Deerfield beach Fl
Was it eaten up or anything?if not, chances are its not connected at the manifold. Are you sure vacuum is the problem? drop down the panel under your glovebox you will see the same black plastic vacuum line and it has a connector where it goes to the hvac module, you can either use a vacuum tool, that would be the smart way or suck on the line going into the vacuum module like I did and make sure you have aspirin ready. if you do that with the car going, you can see if the vents change. its pretty apparent when you start pumping sucking, etc that the vents move from defroster to Vent, to whatever setting you hit on the mode button, oh and recirc will work too.
Originally Posted by Buckmaster
OK....I found that black line that goes under the wheelwell area. Wonder why is goes under the wheelwell? That is the one thing I didn't look at....that is....in the wheelwell where it seems to go........
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Originally Posted by robl45
Was it eaten up or anything?if not, chances are its not connected at the manifold. Are you sure vacuum is the problem? drop down the panel under your glovebox you will see the same black plastic vacuum line and it has a connector where it goes to the hvac module, you can either use a vacuum tool, that would be the smart way or suck on the line going into the vacuum module like I did and make sure you have aspirin ready. if you do that with the car going, you can see if the vents change. its pretty apparent when you start pumping sucking, etc that the vents move from defroster to Vent, to whatever setting you hit on the mode button, oh and recirc will work too.
It has to be vacuum IMO......I think I may be confusing the connection on the back of the manifold (larger rubber tubing) and the small black line (looks like a black wire)......
Last edited by Buckmaster; Jul 24, 2004 at 11:59 AM.
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From: Anthony TX
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St. Jude Donor '08
Yep,, that is it!!
I would cut off a small piece of that black plastic vacuum line and take it to the automotive store and get some rubber vacuum hose to bridge the two pieces!!
Bill
I would cut off a small piece of that black plastic vacuum line and take it to the automotive store and get some rubber vacuum hose to bridge the two pieces!!
Bill
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Originally Posted by Bill Curlee
Yep,, that is it!!
I would cut off a small piece of that black plastic vacuum line and take it to the automotive store and get some rubber vacuum hose to bridge the two pieces!!
Bill
I would cut off a small piece of that black plastic vacuum line and take it to the automotive store and get some rubber vacuum hose to bridge the two pieces!!
Bill
Maybe because it isn't connected..........................
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From: Anthony TX
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St. Jude Donor '08
To get this issue fixed properly you need to remove the battery, the access panel in the rear of the passengers wheel area and nuteralize ALL of the acid, clean and paint the frame if it is corroded,rusting and properly bridge the missing piece of plastic vacuum line. There are alot of vacuum lines in that area and in the wiring harness! Make sure they are intact!
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St. Jude Donor '03-'04
Originally Posted by DocToss
If you just had some manifold work done, couldn't you just take it back and let them check it?