Hi Jimmy,

The click indicates the magnetic clutch on the A/C compressor is engaging & disengaging continually due to...

1. Low R134a charge (yes, could be the evil EVAP!!).
2. A/C compressor needs re-shimming, as Tech has a post on it.

Recharge the system again to see if it holds pressure. If not, blame the evil.


JPN

 

^Thanks for the info Max and JPN!!

Now I know I don't have to spend 300 bucks and get a compressor too (although I probably woudl have tried to re-shimmed it).

Can't wait for school to end...I have a couple projects planned....

 

Hi,

You're going to find this very scary but mine indicates that the AC pressure is 100psi! With that special tool. I bought the car a while ago and I guess that the A/C compressor must be failing. My friend wants to drain it and re-pressurize it but I hear it's illegal. It also makes the clicking sound. I'm guessing my compressor's shot, any ideas? It blows very hot during the day.

 

I have a feeling that you may have tested the pressureon the high side, whose normal pressure is 406-450 PSI. Are you sure you've tested it on the low side?


JPN

 

http://www.sjdiscounttools.com/indgez-1.html This is the tool I used, I put the gauge on after letting the car run for 3 minutes and it says it's in the "danger zone" the needle is on the halfway mark, is there a way to tell if my car model has pressure on the high side or the low side. or maybe the car model has a different PSI requirement. I also returned the gauge and used another for the same result.

 

The gauge was probably reading the actual pressure. No, there should not be so much pressure difference on different models, the correct pressure on the low side is 25-33 PSI as per factory maintenance manual. If you DID test the low side, something would already have failed, but if the system is overcharged, yes the A/C cannot produce cool air as theexpansion valve would not beable to vapourise the refrigerant.

See attached; the low side port has a label on the pax-side strut tower.


JPN

[IMG]local://upfiles/6892/64745620041A408883DCAB92946673C2.jpg[/IMG]

 

>>
c) Connect a recharge kit that has an in-line pressure gauge and check pressure on the low side.
*The correct system pressure is between 25-33 PSI.
>>

Is this low side operating pressure correct for all models?

I have a 1995 850 Turbo Wagon.

The pressure when operating was about 50 psi and I have bled it down to 40 PSI. With engine off the equalized pressure is about 70 PSI.

The compressor runs without cycling, and is blowing about 25 degrees F under ambient (when ambient is about 75-80 degrees F and humidity is not excessively high).

I think I should be getting another 10 degrees below ambient ???

I would really like to find a nomograph so I can properly adjust the pressure.

 

I have a 1991 740 wagon. I am not getting any air coming out of vents when I turn on ac, and no switching between vents when I turn ac vent sellector dial. Does anyone know what I need to repair or replace?

 

I had a 740 GLE and it starting loosing vent pressure when I climbed hills and under other heavy throttle situations. Turns out that it had vacuum leaks in some billows (tennis ball looking things) that require you to remove the dash to repair. $1,200 job at the stealer. You can likely do it yourself if you have some good instructions and a lot of time. Verify that it is the problem before you make that move.

 

Thank you for that info rspi! It sounds like a big job. I am willing to take on the task. I do believe the problem is somewhere underneath or in the dash area.