Edrock

Hey guys, my 93 trans am has a problem with the AC as where the air only comes out of the foot vents and defroster vent. No air exits out of the 5 circle vents on the dash. I have checked all 3 vacuum lines for the system that run into the check valve on the passenger side and they are all intact. Anyone know what could be causing this problem?

Spamfritter

iTrader: (1)

I have the same exact problem on my car. I know the dash was messed with on my car as the passenger side air bag is missing. This leads me to believe that I may have a vacuum leak where the line comes back into the firewall and into the dash somewhere. I also replaced the check valve on my car, though it had no effect.

I'm curious to see what other responses are on this issue. That's as far as I've gotten with mine.

Tyler Dietzenbach

iTrader: (5)

I had this problem on a Cutlass about 15 years ago. There are blend door actuators that control what vents open and close. In my case they were behind the glove box in that car. I had to replace them.

Spamfritter

iTrader: (1)

I'm wondering if that's my issue given that the passenger side airbag was removed. It's quite possible that things were screwed up inside the dash when that was done or something was left disconnected. Unfortunately, it's 1,000 degrees in my garage and I need to move the drive train donor car (another Camaro) out to open the passenger door for removing the dash on my Camaro.

Edrock

So something else I am wondering is that no matter where you turn the ac dial whether to AC, max, or just blower, the amount of air coming out is exactly the same. Also when you turn off the AC, it no longer makes the "tsssssssssss" sound. I know that sounds ridiculous but that is what is also going on

Spamfritter

iTrader: (1)

I have precisely the same issue as you.

Edrock

Its very annoying how no one else has come across this

Spamfritter

iTrader: (1)

Unfortunately, if you look at a lot of fourth generation Camaro and Firebird cars, you'll find their air conditioning doesn't work or isn't even in the car anymore. Generally speaking, the AC system is fairly simple, yet many of the same guys who dive deep into the electronics or the mechanical workings of these cars treat AC like its some magic or forgotten science that no one understands. When faced with having someone else do it, the labor costs are rather extreme and many of these AC systems simply don't get repaired. Also, many of these cars get cut up for track use and AC isn't a priority for most people. These are also often weekend cruisers, and thus, fair weather cars. Again, minimizing the priority on AC repairs.

I'm in Texas. It gets hot here. Screw that.

The reality is, the entire AC system is actually relatively cheap and easy to work on. My car has almost an entirely new one and it really wasn't that hard. The vent issue is new, and I pursued the usual vacuum leaks and all of that. However, this particular issue is a new one. The car I pulled the drive train out of didn't do this, so I have the parts I need to fix this, but I'd like to know what could be wrong so I can proceed without swapping everything over from the other car.

Edrock

So I took out the ac controller(the thing with the dials) and there is a vacuum line attached to the bottom which i assume is the one that comes through the firewall. What i am going to try when i have some time is disconnect both ends of that line and just take another piece of line and plug it in both sides and see if that works. Then i will know if that line is my problem

Spamfritter

iTrader: (1)

Very interested in your results on that. I replaced my HVAC controls in the car as the face plate was cracked on the original one.

2ToeRacing

iTrader: (5)

Its a vacuum line cam\e/broke off from the back of the intake. reach your hand in the rear of the intake from the driverside and you'll feel it. I think theirs only two

Spamfritter

iTrader: (1)

That's not the issue in my case. I've checked that one already. That said, there is a coupler in the middle of it like it's been repaired. I may get a new line and test that separately. Also, there isn't a vacuum line going direct to the HVAC controls that I could find. There is a thicker line that does, but nothing like the one that goes through the firewall. I'm not sure where that terminates at.

JimMueller

iTrader: (9)

The blend doors behind the dash are operated by vacuum; try a smoke test on the vacuum lines. I had a similar problem on my '98 A/C, and it was related to a vacuum tank that's on my frame rail near the passenger horn and fog lamp. The hose that T'ed off by the cowl and went to the vacuum tank came off the tank nipple. Ironically, when trying to reattach the line to the tank the line snapped, so I just capped it at the cowl for now and my A/C now works fine. However, I hope to make a proper repair in the future.

Edrock

So now that you said you replaced your controls i am a little more concerned on my issue. I thought it may have been the controls because i read that when the controls crap out they default to defroster vent and feet vent and no cold air. Considering that is exactly what is happening i figured that must be it. But now that you say that, i fear the problem may be somewhere else. I havent gotten around to bypassing that vacuum line yet however.
Also, it is not even trying to turn the compressor on, which led me to believe again that it is a control issue

bigbomber5

This was what caused my issue on my 02 TA when it would only blow through the windshield and foot well

Spamfritter

iTrader: (1)

I hadn't checked the lines over there. I will have to do that.

Edrock

So i checked all my vacuum lines and they are intact. I strongly believe that my controls have failed. The compressor isnt kicking on when i turn ths switch which leads me to believe that the controller is telling the system to do something else. Also my controller didnt work exactly right before as the temperature dial did not work. So now I believe that both dials have failed. I think its time for me to order a new controller

Edrock

The AC controls are now installed however i am having the exact same issue.

Tyler Dietzenbach

iTrader: (5)

Did you check the actuators and that area behind the glove box yet?

Edrock

How would i check this to see if its working?