Vents only blow through defrost
09-17-2012, 03:40 AM
#1
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Vents only blow through defrost My 2002 Trans Am only blows through defrost when it's on regardless of which option is selected, but turns off when set to off. Would it be a switch?
09-17-2012, 11:08 AM
#2
Vent selection is controlled using vacuum from the engine. There is a hard plastic line that feeds the hvac box. Check under the hood near where the PCM is mounted and look for the black plastic line with s 90-degree rubber fitting on it and make sure it is connected and not damaged.
09-29-2012, 06:19 AM
#4
That should be for the air injection and unrelated.
I'll bet you anything you need a new 2 way T valve that looks like this
I had the exact issue with my Camaro when I bought it. Replaced this, and it's worked ever since.
It's a Dorman HELP! part #47150
About 7 bucks at Autozone or Advanced
The box looks like this
I'll bet you anything you need a new 2 way T valve that looks like this
" /> I had the exact issue with my Camaro when I bought it. Replaced this, and it's worked ever since.
It's a Dorman HELP! part #47150
About 7 bucks at Autozone or Advanced
The box looks like this
09-29-2012, 09:42 PM
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I asked the same thing in another post earlier but no one would respond... I kept toying around looking for a cause and none of those was the issue. The check valve worked fine, no line leaks and the HAVC control worked just fine... Needless to say I got it to working but have no idea how...
You might pull open the glove box so that you gain access to the HVAC vac lines. You can unhook the connector and see if you're getting a vacuum off the black line coming from the firewall. You just place your finger over it so as to create a seal and see if it's pulling a vacuum... If so then the problem isn't coming from under the hood... If your not getting a vacuum then check other areas as suggested and the line coming off the vacuum booster behind the master cylinder.
You might pull open the glove box so that you gain access to the HVAC vac lines. You can unhook the connector and see if you're getting a vacuum off the black line coming from the firewall. You just place your finger over it so as to create a seal and see if it's pulling a vacuum... If so then the problem isn't coming from under the hood... If your not getting a vacuum then check other areas as suggested and the line coming off the vacuum booster behind the master cylinder.
