?? Air Conditioning airflow slows/stops ??

**scStormChaser** · 08-17-2014, 04:13 PM

Hey guys. Anybody had issues where the AC stops or significantly reduces air flow after about an hour of use?

I can be driving with the AC on and then the amount of air coming out the vents drops to almost nothing. I can crank up the fan speed, the blower spins up to high rpm, but it doesn't increase the airflow, almost as if the vents were closed or blocked off. The AC blows hard and plenty cold during the first hour of use so its nothing to do with temperature. I replaced the blower motor entirely after this started happening just to be sure that wasn't the issue but no luck. Its almost like the vent control closes up the vents and stops the air from coming out after about an hour for some reason. Any help would be GREATLY appreciated!

**pajeff02** · 08-17-2014, 05:13 PM

Is your drain tube clogged? Could be icing up.

**theorangeguy** · 08-17-2014, 05:17 PM

My 99 camaro used to do this and it was the drain tube. Always seemed to do it on long trips...otherwise it worked fine because it was never on for more than an a couple of hours at a time. It took mine about 2-3 hours to do what your are describing.

**pajeff02** · 08-17-2014, 05:25 PM

He could have higher humidity in Florida and that is why his takes less time to ice up.

**scStormChaser** · 08-17-2014, 05:46 PM

So are we saying slow ice buildup on the evaporator is stopping the airflow all together? Is it easy to clean the drain tube? I have no idea where it is. The little bit of air that does come out is still very cold, just very little air flow.

**pajeff02** · 08-18-2014, 02:29 AM

The drain tube is on the passenger side of the car, back by the firewall, and hangs down under it. If you run the AC while parked (or park the car after running it for a while) you should see a puddle of water under this area. This water comes from the drain tube. It is a thin rubber hose that has the end pinched almost shut to keep outside debris from entering the hose.

**RONS98TA** · 08-18-2014, 03:26 AM

Run your car until the airflow is reduced to almost nothing. Then hop out of your car, open the hood and look in the direction of the passenger side firewall. I bet you will see a completely frozen ac lines. This can also be caused by a leak in the ac system, or a low freon charge.

**scStormChaser** · 08-27-2014, 01:24 PM

Originally Posted by RONS98TA

Run your car until the airflow is reduced to almost nothing. Then hop out of your car, open the hood and look in the direction of the passenger side firewall. I bet you will see a completely frozen ac lines. This can also be caused by a leak in the ac system, or a low freon charge.

You are right, All the lines are frozen up under the hood after about an hour. So if the lines are frozen up, that means the evaporator is also frozen? Would this block air flow? It's still cold even when it's frozen, just not much air blows out.

**RONS98TA** · 08-28-2014, 03:50 AM

Yes. The evaporator inside the dash will be a complete block of ice. The fan cant blow through the solid piece of ice, it needs to pass through the veins. The evaporator is the exact same looking as your cars radiator. So imagine that in a smaller form. You can go to almost any automotive store and buy a can of freon/sealer. It's really easy to use. More than likely you have a small leak somewhere in your system. The freon/sealer combo should solve your issue. I've used this type of product on 8 different cars and trucks. It worked on 6 of them but didnt on 2 of them. One very important thing is, after you use the freon/sealer kit, you must keep the a/c on for about an hour to get the sealer completely circulated through the entire system. I didnt do this at 1st, which I think is why it didn't work on said 2 cars. The sealer will not fix a leak if the leak is the compressor shaft seal. It's a bit of a gamble, but the freon/sealer is fairly cheap enough to try it. The alternative is taking it to an automotive shop and get charged an arm and a leg to find the leak, repair or replace whatever, refill with freon, plus labor. Big $$$$$. Good luck my friend, but I'm pretty confident the sealer will work for you.

**scStormChaser** · 08-28-2014, 10:48 AM

Originally Posted by RONS98TA

Yes. The evaporator inside the dash will be a complete block of ice. The fan cant blow through the solid piece of ice, it needs to pass through the veins. The evaporator is the exact same looking as your cars radiator. So imagine that in a smaller form. You can go to almost any automotive store and buy a can of freon/sealer. It's really easy to use. More than likely you have a small leak somewhere in your system. The freon/sealer combo should solve your issue. I've used this type of product on 8 different cars and trucks. It worked on 6 of them but didnt on 2 of them. One very important thing is, after you use the freon/sealer kit, you must keep the a/c on for about an hour to get the sealer completely circulated through the entire system. I didnt do this at 1st, which I think is why it didn't work on said 2 cars. The sealer will not fix a leak if the leak is the compressor shaft seal. It's a bit of a gamble, but the freon/sealer is fairly cheap enough to try it. The alternative is taking it to an automotive shop and get charged an arm and a leg to find the leak, repair or replace whatever, refill with freon, plus labor. Big $$$$$. Good luck my friend, but I'm pretty confident the sealer will work for you.

Thank you sir. Took your advice and charged the AC system. Following the instructions, the chart on the bottle said the pressure should read 45-55 psi at the ambient temp of 80-90 degrees. The pressure gauge read about 35 psi before charging. After spending about 15 mins slowly charging the system, trying to be careful not to over charge, I nearly emptied the entire 22oz bottle. However the pressure gauge still read just a little above 35psi. The AC still blows cold. I ran it for an hour, not freezing up. However its been a few weeks since my last freeze up, but the humidty has lowered alot since then.

I'm still confused though...why did the pressure not increase at all during and after the charge???? I would think it would go up SOME after almost putting in the entire bottle! Did i do something wrong?

**RONS98TA** · 08-29-2014, 07:01 AM

If it's working and you followed the instructions, you are good. I don't know all the specifics as far as what the gages should read, I just kinda wing it and it works out. I did some reading up on it once before just for a better understanding of how the system works, but I honestly don't remember the specs on all of it.