nightman06

AC was working great up until about two weeks ago. Then I went home for about two weeks. Came back and tried to turn on the AC. I got "air" out the vents but not cold air. Also, I had a very noticeable knocking only when the AC was selected. When normal vent selected all was fine. I could feel the knock in the clutch when I lightly depressed the peddle. This problem went on for about a week. I would only engage AC for about a sec to see if it was still the same. Tried this about 6-7 times over a week period. Now it wont even stay engaged. I turn it on, it knocks around for 1-2 secs and stops. The compressor is turning. I can see that just by looking. And the pressure in the AC lines is good.

PLEASE HELP!! Its about 200 degrees here. Im dying. Thanks!!

nightman06

Someone must have seen this at some point.....?

jimcork1

No but now I have.

You said the AC line pressure is ok. So what is AC line pressure ?
High Low? while running? stopped?

casslaw

The knocking noise might very well be your a/c clutch taking a dump on you. If it seizes or the clutch goes out, you're gonna be in trouble. I just replaced the compressor on mine. It wasn't fun, but doable if you're good with tools. I used a re-man compressor and now it blows me out of the car. If you have pressure and no a/c either the clutch isn't engaging or is just bad gone. Sorry

TEXHAWK0

It seems like that you would not be able to check the high and low side pressures if the compressor was not working.
Maybe the compressor is working but the clutch is slipping, and getting ready to fail. Are you sure a low freon pressure switch is not keeping the clutch from staying engaged?

nightman06

If I can see the compressor spinning than wouldnt that indicate the clutch is still good?

I know it sounds cheesy and probably inaccurate, but I just used one of the A/C refills with the gauge on it. Turned the AC on max and plugged the AC into the valve. It read green.....

Im very handy with tools, and have done numerous heavy jobs on this car. However, Im really in the dark when it comes to the AC system. A step by step, or process of elimination would really help here. THanks so much guys!!

jimcork1

If I can see the compressor spinning than wouldnt that indicate the clutch is still good?

NO. Make sure the flex plate is turning not just the pulley.


I know it sounds cheesy and probably inaccurate, but I just used one of the A/C refills with the gauge on it. Turned the AC on max and plugged the AC into the valve. It read green.....

NO. This will only measure low side pressure and not determine if the compressor is running. In addition if you have a can attached it will show can pressure and not give a real pressure reading.

1) Turn the flex plate by hand to see if it is free and the compressor turns with no roughness.

2) Run the system and look at the pulley / flex plate to see if they are all turning

3) Read the high and low pressure readings with a gauge set to determine how the system is operating. This will give you the answers.

So far you have insufficient data to help solve the problem.