air duct problem
 

96 coupe: has anyone had the air going to the defrost when turning on the a/c. after a long while the air comes out of the vent ducts like it should? what is causing the air to delay such a long time?

RE: air duct problem
 

Welcome to the forums there...

How 'bout if the vehicle is TOTALLY warm, and THEN you turn on the air? Try that next time you motor up.

RE: air duct problem
 

warm or cold same thing. i can be driving on the road for a long timetill it operates normal. i stop at a store turn the car off, get back in go about my way back home and still no air through the vent ducts for a long time and then slowly the air starts to come out normaly through the vent ducts like it should. what operates the duct doors behind the dash?

RE: air duct problem
 

Does your car have ATC (Automatic Temp Control)? Sounds likeyour mode actuator is leaking vacuum or is lazy.

RE: air duct problem
 

no ATC

RE: air duct problem
 

How 'bout the volume of air before and after the 'correction'...

When it is coming out of the defroster ducts, is it a LOT of air (fan on high)? Is it hot? Is any coming at all out of the dash ducts?

When it switches, do you hear a duct door close? Can you then make it go back to the defroster ducts with the defrost switch?

If you can make it go back to the defroster duct with the defrost switch, what happens then when you switch it back to the dash? Does it take a long time again, or is it right away?

RE: air duct problem
 

volume of air is correct for the switch setting (speed)
the air coming out of the defrost at time when i turn the a/c on is according to the temperature, no problem with speed setting
the air is not comming out the dash ducts yet till a few minutes later
no noise when it swiches, when i switch it back to defrost and then back to dash vents it still takes awhile to blow out the dash vents. what mechanism moves the duct gate. is it electrical? a co worker has a chev. truck and his duct gate operates electricly. i always thought it was vacumn till he showed me different. do you think it is the same

RE: air duct problem
 

You have a '96 too,huh?? Well,I've been fortunate to not have this problem,but I really hope you get this resolved.A few of us here at the forum will help you,even if it's not me.....just let me know what you find to fix it,will ya?? I might have the same problem some day(mine has almost 114,000 trouble-free miles),maybe you can give me and the rest of us a good fix-it tip!! Welcome to the forum! A friend,Joe.

RE: air duct problem
 

well joe you are one of the fortunate ones. if i find a fix i'll post it. as you may look in the forum i have 2 issues. the air duct and a battery drain. the battery drain is a more problem though. thanks

RE: air duct problem
 

Have you checked the vacumn valveunder the pass/side fuel cover. Just a thought..........

RE: air duct problem
 

seen that valve just didn't know what it was for. will look into it. it should work in one direction right? if it doesn't hold on the back side i guess that would be an indication. could be why the enginehas a tad idle miss. like carburator would out of adjustment. course mine is fuel injected. but a small vacumn leak will cause that. it isn't very much but you can feel it in drive with brake on at a traffic light. will let you know what i find on that valve. thanks

RE: air duct problem
 

I believe your mode actuator is vacuum controlled and if it is, either there is a vacuum supply leak or the actuator is leaking. You'll have to gain access to the vacuum harness to test for supply vacuum. Should have at least 17 to 19 " of vacuum supply, if not then there is a cracked plastic vacuum line.

RE: air duct problem
 

i'll look into that. i see that you are a certified mech. right now i have a more serious problem, if you look at my other thread. i talk about battery drain. i did a test with a volt meter, between the negative cable and neg. post. it is drawing more than it should a normal draw is anywhere between 24-27 mil.amps. for the computer.i'm getting around 33. i pulled the 20amp fuse for the interior lights and it dropped to a normal draw. after pulling all fusesone at a time that was the only one that showed a large draw. the fuse gives current to all lights in side that includes dash, and dome, and courtesy. my question to you is i'm sure there is a timer type relay or some thing under the dash that controlls the current. when i open the door the courtesy lights come on and when i shut the door they go off after a few seconds as normal. also when i turn the key to start the engine. my theory is that there is a relay stuck in the closed position. the timer seems to be working normal. i have pulled the 20 amp fuse charging the battery and i will let the car stand for another day and then check the voltage to see if it drops. have you ever come across this thanks for any info this has been a thorn under my saddle[&:]

RE: air duct problem
 

The 20a fuse is not the charge side of the alternator. Disconnect the big red wire from the back of the alternator as there is no fuse to control that. That will tell you if your internal voltage regulator is shorted pulling power away from the battery.

RE: air duct problem
 

it's the second new alternator in a row, but i will try it after i try the fuse thing on the light theory thank you.

RE: air duct problem
 

I am reasonably sure your car ahs vacuum operated air flow controls and an electric temperature door. It blows out the defrost when there is no vacuum, There is a vacuum connection to the intake manifold with a one way check valve under the hood that connects to the heater control head. I would check that first. If the one way valve is bad it will let it go to defrost when it is turned off, , or if there is a vacuum leak anywhere in the system, it will also go to defrost when you turn it off. You probably need to obtain a hand vacuum pump and start applying vacuum to the various components one at a time until you find the one that is leaking. There should be a connector at the back of the heater control head with half a dozen vacuum hoses that allneed to bne checked

RE: air duct problem
 

I have a '96 CE with the same problem, although I have ATC. My cruise control also does not work, so I am pretty sure it a vacuum leak....SOMEWHERE ?? I put in a new vacuum bladder (the little ball just in front of the left front tire) which was not connected due to a broken nibble, unfortunatley this didn't help anything. Any help would be greatly appreciated, as I can't seem to pinpoint the leak.

I have a 94 and my dash vents do not get air either, just stopped a couple months ago. Am trying to find resolution also. All air controls work fine but nothing thru dash vents. I used to hear the vent close or open, but nothing now. I am thinking vacumn also

This may be the source of the problem?

http://forums.corvetteforum.com/c4-g...ac-access.html

Found a fix for dash vent not opening. Pop off the plastic protector on the passenger side of the engine, you will see a vacumn line with 2 outputs, one is for dash vent the other for cruise control. My plastic piece was broke and was able to use black tape to temporarly repair the part until I can get a replacement for the 3 way vacumn connection. Would think this would be the second thing I would check after checking the fuse by the passenger door.

after validating the fuse is ok by the passenger side of dash, pop off the plastic cover on the passenger side of engine and look at the vacumn valve. Mine was broke and was able to use black tape to fix it until I can get a replacement. This vacumn valve controls both the dash vent and the cruise control. Would think this will solve problem.
From Joe