Half of front vents blowing cold, other half blowing warm?

[Oldsrip]

Hi guys,

I reopened this last week. Thanks for the updates and feedback.

I replaced then condenser, radiator and fans the other day. But I had to go out of town so I didn't evac and recharge the system yet.

The one other question I had, is there any kind of vacuum devices in the top center dash vent? I can hear a hissing when I turn the blower fan on.
It may be normal, I don't drive this van.

Thanks,

Joe W.

[Shuggie]

New here. My ac on my chevy trailblazer ext ls v8 5.3l has same problem only blowing ac on one side. Charged ac with two cans and still doing same thing....anyone tell me what to check out on it?

[Tech II]

Usually one of two problems......low refrigerant, or actuator problem.....

Check actuators first .....with a warm vehicle, turn A/C off, use vent position, and blower on Hi.....command full hot...temp should be the same on both sides....now command full cold with A/C off.......temps should be the same....

If they are, then the actuators are ok.....even though you added two cans, it's possibe there is air in the system......a low charge or air in the system, can cause this problem...i recommend an evacuation, and adding the proper amount by "weight"....

[Shuggie]

That's exactly what it is air in the system i let some out as i put the refrigerant inside because it had alot of pressure. Guess there is a special tool you got to have to vacuum it out. So i been told. Thanks for the help.

[Tech II]

Well, the system has a leak......you need to find the leak, repair it, evacuate the system(pull a vacuum), then add refrigerant by WEIGHT....

[jdautoforums]

Hi Tech II,

I have a Toyota Camry 2012 model having dual temperature control zone. I am having same issue. Driver side air vent blows hot air where as passenger side air blows cold air. I followed the instruction you had given in previous posting...."Check actuators first .....with a warm vehicle, turn A/C off, use vent position, and blower on Hi.....command full hot...temp should be the same on both sides....now command full cold with A/C off.......temps should be the same...."

The temperature is same in both case. I did not switch the A/C on. I did this with temp. control Hi and Low.

Please let me know what could be the problem. I saw the coolant level is just above Low level although it doesn't give any indication at dashboard.

Thanks!

[Tech II]

Well, if you have the same hi and lo temps with the A/C off, then the actuators are working ok......

If you command full cold with A/C on, and one side is not as cold as the other side, that is usually an indication of low refrigerant(this has nothing to do with a low coolant level)......basically what happens is, when there is low refrigerant, the refrigerant enters the evaporator, and "short circuits" through the upper part of the evaporator, less goes through the lower half.....one side uses the upper half of the evaporator, and the other side uses the other lower half....thus the discrepancy in cooling....

[jdautoforums]

Hi Tech II,

I found your analysis quite logical. I bought a refrigerant form walmart and recharged the a/c myself. It worked! If there is any leak, I don't know how long it will last but as of now it is working absolutely fine. My Toyota dealer had asked $61.50 for diagnosis and had quoted apx. $265 for a/c recharge. Thank you so much! The car is 4 years old. Is it normal for refrigerant level to go so low or there possible leak? Thanks once again.

[Tech II]

No it is not normal......you have a leak.......if your A/C works normally for a long period of time, obviously you have a small leak.....if the same thing happens again, in a short period of time, you have a much larger leak.....

[nswright]

Good morning I have a 2005 Chevy Tahoe that's doing the same thing about how much would something like this cost to be fixed?

[brcidd]

It will cost a pretty penny if you go to the stealership-- find someone who can extract and weigh the remaining refrigerant and then you'll know how hard to find the leak..loss of 10% is no big deal-- loss of 90% is a big deal-- so have it leak checked and dye checked- if you have rear air (you did not state the model yr) then rear lines are highly suspect for leaks..

[nswright]

Originally Posted by brcidd

It will cost a pretty penny if you go to the stealership-- find someone who can extract and weigh the remaining refrigerant and then you'll know how hard to find the leak..loss of 10% is no big deal-- loss of 90% is a big deal-- so have it leak checked and dye checked- if you have rear air (you did not state the model yr) then rear lines are highly suspect for leaks..

Hi and thanks for replying it's a 05 chevy tahoe with a third row, so yest I have rear air as well I believe