A/C problem 94 LeSabre

[sebaz]

Hello,

My mechanic recharged my A/C about two weeks ago. At first it was fine, but after a week and a half the cold air was gone and even worse, the strangest thing happened, the two right vents began blowing warm air with the A/C on max and the slider all the way to cold. The two left vents just blow regular temperature air.

I bought a can at Walmart from Interdynamics, it's a very simple system, just a hose with a gauge and the can. It says to turn the engine on, the A/C to Max and to read the gauge. The problem I have is that it's not stable, it goes up and down between about 20 psi to 45, which according to the chart it means it's full, but how can I know for sure which is the real reading, if it oscillates between 15 or 20 and 45? I made sure the coupler is well attached. I can tell that this oscillation happens because the compressor (I suppose that's what it is, because I don't know anything about mechanics) turns on and off every couple seconds. When it's off, the gauge goes down, when it's on, it goes up.

Is this because the product I bought is cheap quality, or because my compressor is dead? I began charging it for a bit and I checked the air and it was cold, but then I checked again a minute later and it was normal temperature again. But still, when it was cold, the two right vents were blowing warm air, which I showed to my mechanic and he told me that he had never seen such a thing in his 20 years of fixing cars.

I read a few other posts here about A/C recharging, but nothing shows my specific problem. Can anyone please show me the light on this?

Thanks,

Sebastian

[HotZ28]

Your low side switch is set to turn on the compressor @ 45 psi and off @ 27 psi. It sounds like you may have a leak if it was just serviced. If the compressor is cycling off-on ever few seconds, you are low on freon! Try warming the freon can in warm water (105 deg) prior to installing it. You need to get around 35 psi on your guage with the compressor running and the freon turned off. You may have to take the coupler off and reinstall it to get an accurate reading. Also, after you get the compressor cycling normally, turn off the air condition and then turn it back on to reset the blender door. It could also be an actuator, however you need to get the freon resolved first.
There is nothing worng with Interdynamics, they have been in the business for many years.

[sebaz]

Thanks for your reply. What is the normal cycle for the compressor? Also, if the gauge oscillates between 20 and 45, which one is the true reading?

Thanks,

Sebastian

Originally Posted by HotZ28

Your low side switch is set to turn on the compressor @ 45 psi and off @ 27 psi. It sounds like you may have a leak if it was just serviced. If the compressor is cycling off-on ever few seconds, you are low on freon! Try warming the freon can in warm water (105 deg) prior to installing it. You need to get around 35 psi on your guage with the compressor running and the freon turned off. You may have to take the coupler off and reinstall it to get an accurate reading. Also, after you get the compressor cycling normally, turn off the air condition and then turn it back on to reset the blender door. It could also be an actuator, however you need to get the freon resolved first.
There is nothing worng with Interdynamics, they have been in the business for many years.

[HotZ28]

The cycle time varies by ambient temperature and fan speed. I forgot to mention, when you add freon, be sure the fan is on high. Cycle "time" has nothing to do with real time; it depends solely on pressure within the system. When the compressor comes on, your low pressure will drop and when it cycles off, it will go up. That would explain the fluctuation you see if the compressor is cycling every few seconds. The disposable gauges that come with the Wal Mart kits are not very accurate. I would remove the rain shield from the firewall and place your hand on the accumulator to feel how cold it gets. When the accumulator feels like a cold can of brew and the compressor stays engaged, you should have cold air from the vents.

[stuzman]

Originally Posted by sebaz

Hello,

My mechanic recharged my A/C about two weeks ago. At first it was fine, but after a week and a half the cold air was gone and even worse, the strangest thing happened, the two right vents began blowing warm air with the A/C on max and the slider all the way to cold. The two left vents just blow regular temperature air.

I bought a can at Walmart from Interdynamics, it's a very simple system, just a hose with a gauge and the can. It says to turn the engine on, the A/C to Max and to read the gauge. The problem I have is that it's not stable, it goes up and down between about 20 psi to 45, which according to the chart it means it's full, but how can I know for sure which is the real reading, if it oscillates between 15 or 20 and 45? I made sure the coupler is well attached. I can tell that this oscillation happens because the compressor (I suppose that's what it is, because I don't know anything about mechanics) turns on and off every couple seconds. When it's off, the gauge goes down, when it's on, it goes up.

Is this because the product I bought is cheap quality, or because my compressor is dead? I began charging it for a bit and I checked the air and it was cold, but then I checked again a minute later and it was normal temperature again. But still, when it was cold, the two right vents were blowing warm air, which I showed to my mechanic and he told me that he had never seen such a thing in his 20 years of fixing cars.

I read a few other posts here about A/C recharging, but nothing shows my specific problem. Can anyone please show me the light on this?

Thanks,

Sebastian

Just a few notes to add to HotZ's comments. First, always use pure refrigerant without any additives such as stop-leak, seal conditioners, etc. These additives can create more problems than before, especially the stop-leak. You should get the leak fixed as you're just wasting money with refrigerant. Also, it would be a good idea to change the accumulator followed by pulling a vacuum on the system. You can find other info with auto a/c experts at this forum. www.autoacforum.com