How do i know if the A/C compressor is going out?

Discussion in 'SN95 4.6L Mustang Tech' started by mat82284, Sep 9, 2009.


  1. mat82284

    mat82284 Member

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    Today my car has been acting weird. I was driving and my A/C cut out, then my idle started bouncing from 700rpms to 1100rpms. It kept bouncing in till i turned the A/C switch off. When i switched it back to the A/C knob the idle started bouncing again. The air being blown was warm. I just left it on the on position even though my idle was bouncing. The A/C turned back on after 2-4mins. After 10 more mins It turned back on and the idle again bounced around.

    What could cause this? Could my compressor be going out? What about a fuse that could have blown but somehow creating a small current? Or maybe its a wiring issue?
     
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  2. trombonedemon

    trombonedemon Well-Known Member

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    First do a compression check, find the high side and then the low side. Then listen for the clutch to engage, and for the clutch to engage you need to have the right pressure to send it a message. I think your compressor is a piston, which has bearings, you would hear kind of a squealling noise if your bearings go bad. But first check to see if your lows and highs are in the general area. Your a/c should cool on 70 degree day about 40 to 32 degrees. It sounds like your pressures are a little out of whack, and if you pressure switch is only picking up some of the time then your clutch will in engage on and off thus the rpms are going to be funky. Again check you pressures. Your compressor sounds like its fine.
     
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  3. BlownFiveLiter

    BlownFiveLiter have car, will race....wait, it doesn't run

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    I bet the AC is low, so the compressor is cycling. Toss some gauges on and see where your charge is.
     
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  4. mat82284

    mat82284 Member

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    ok sounds good. I have a AC recharge kit that is just sitting here so ill hook up the gauge and check the pressure, then add some if needed. Do i connect it to the high or low side?
     
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  5. BlownFiveLiter

    BlownFiveLiter have car, will race....wait, it doesn't run

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    Low side.
     
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  6. SVT32VDOHC

    SVT32VDOHC waiting for the next hack atta
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    MY 97 Cobra did this it ended up being the pressure switch on the firewall in the evap line. I switched it out with one from a Windstar and it fixed it.

    The A/C compressor doesn't really go bad. The bearing does. It's one bolt and then a snap ring and the bearing and pulley comes off. I've had those go bad too, but this won't cause cycling/idle problems, you'll just get a horrible burning smell and screeching sound as the bearings seize up.
     
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  7. mat82284

    mat82284 Member

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    Ok i tested the A/C. I dont know what port i checked but there was too, one with a green cap and one with a black cap. The green cap said service port so i figured its the wrong port so i connected my gauge to the black port. My gauge read about 165psi. Is that correct? What psi should it be reading?

    Second the A/C no longer comes on at all anymore, the idle just bounces when turned to the A/C position.

    SVT32DOHC that pressure switch, where is it located? Does anyone know where its located on a 2000 2v gt? Also whats the pressure switched called, is there a part number?


    Anyone have a photo of the A/C Low side???
     
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  8. mat82284

    mat82284 Member

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    I don't know how it happened but the pressure sensor was coming loose and i tightened it and used electrical cleaner on the harness and the A/C blows cold again :) thank everyone!
     
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  9. trombonedemon

    trombonedemon Well-Known Member

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    Yea man, we are hear to over think the problem so you don't have too.:D Hey sounds like a commercial:rlaugh:. But, now I know what else to check if my a/c stops working.:hail2:stangnet.
     
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