Defrost Issue and AC

Discussion in 'Gen 3 Prius Main Forum' started by GreenTerrorPrius, Oct 13, 2020.

  1. GreenTerrorPrius

    GreenTerrorPrius Junior Member

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    I have 2 issues going on:
    1. The car will not defrost in the front (the back seems to work). Esp on humid mornings here in So Fla. I have tried all the settings etc but not much luck at all (Also what would be the optimal setting for this in south florida, outside air?? or recirc air?? also what temp should I use?.) I did find out the AC blows cold air even when AC set to off if you have the front defrost selected.

    2. The AC will only blow cold air after about 1 mile (maybe a big longer) of driving (for first mile just blows regular air non cold air). If I drive 10 miles, and then run into the store for 5 minutes, when i start the car back up it will blow cold air immediately. So my conclusion is the AC will blow cold air when engine is warmed up so to speak

    The first issue is the biggest as I can basically not see out of car unless use wipers but sill kind of foggy.

    Any suggestions on where to start looking.
    Next question, should I bring to an AC shop or a Prius Specific shop?

    thanks
    GTP
     
  2. Pluggo

    Pluggo Senior Member

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    Select outside air and high fan speed. AC is supposed to operate when the defroster vents are selected and the fan is running. A little bit of heat will help, especially if the AC is so cold that you’re using your wipers to clear condensation on the outside glass.
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    I think your slow-to-start AC is the first thing you must address, might be the only thing. I'd use dealership, and pray they know what they've doing. Go in asking lots of questions, verify they know what the issue is: you don't just want a bandage AC service that doesn't resolve the slow start.

    One quibble I have with Toyota's vent system too: why-oh-why don't they have a regular vent mode where ALL the air goes to the windshield, not half'n half windshield/feet.
     
  4. Maarten28

    Maarten28 Active Member

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    Slow starting or non-functioning AC sounds to me like you need to have the AC checked and probably filled.
     
  5. ASRDogman

    ASRDogman Senior Member

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    If you press the defrost button on the right side of center console, next to rear defrost,
    all the air goes to the widshield. Or at least 95% of it does.
    At least it does on my Prius. I remember checking it when I first go the car.


     
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  6. tvpierce

    tvpierce Senior Member

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    The AC removes moisture on the inside of the windshield. The wipers remove moisture on the outside. If your wipers are removing the problem condensation, your AC isn't the problem.
     
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  7. GreenTerrorPrius

    GreenTerrorPrius Junior Member

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  8. tvpierce

    tvpierce Senior Member

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    Sorry, I couldn't read through that digital dumpster fire on the Beetle forum -- it made my head hurt.

    I think this is operator error. Are you trying to use cold air from the AC to remove condensation on the outside of the windshield? If so, that's not going to work.
     
    #8 tvpierce, Oct 14, 2020
    Last edited: Oct 15, 2020
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  9. Grit

    Grit Senior Member

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    :LOL:
     
  10. GreenTerrorPrius

    GreenTerrorPrius Junior Member

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    HAHA Alfred E Neuman, No dont think operator error, OK , lets forget the defrost issue for a bit. As another poster said need to fix this main issue first:
    1.basically sometimes it takes the AC a long time ( a mile or so drive) to kick in and blow cold air. Sometimes it blows Cold AC immediately.

    Perhaps:
    Some type of Relay issue
    AC clutch issue
    Temp Sensor issue

    AC blows ice cold when working.
     
  11. Grit

    Grit Senior Member

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    Why even post this in the first place then :whistle:
     
  12. orenji

    orenji Senior Member

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    Have the compressor checked. It could be failing.
     
  13. lech auto air conditionin

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    Let’s get back to basics. Keep it simple.

    1: What was the method that was used to recharge the air conditioning ? (. Example it was completely recovered, than a vacuum pump was put on it, and then it was recharged by weight ?)

    But for some reason even that doesn’t mean it’s done right since most machines over 5 to 8 years old or plus or -2 or 3 ounces from what they say they put in. I got a couple cars coming to me every week that just came from shops that required one quantity of refrigerant added but when I recover it’s never what they say it was and that was the only reason the air-conditioning is not operating properly.

    Two days ago I was called into a shop who is having problems technician punched in .9 pounds to be added to the car. The car did not operate properly so the technician removed refrigerant in their machine recorded and only removed .7 pounds.
    Technician recharge the car again with .9 pounds car still did not work properly so the technician recovered it and only pulled out .7 pounds.
    The new $5000 machine was less than a year old. Being 2/10 of a pound off on a Prius is a near death sentence on AC performance.

    This afternoon‘s car came from a Mercedes specialist shop who just performed the air conditioning yesterday the owner drove away and when it got hot the AC did not perform well the next day so I got a call.
    The invoice from the Mercedes special shop said they charged a car with 1000 g exactly what it should have and there was no leak.
    I recovered the refrigerant this afternoon and only 780 g were in the system this was their performance problem. There is no leak in the system the accuracy of the scales on some of these machines are pathetic after a few years.

    Do you have any pressures to give us high side pressure low side pressure outside ambient temperature at the time of taking the pressures.

    hopefully warm late afternoon when it’s 80° plus. All windows and doors open in Fresh Air mode . Record high side and low side pressure inlet air temperature going to the air filter outlet air temperature leaving the duct Dash

    Repeat this with all doors and windows closed in recycle Mode Record pressures and temperatures.

    If possible only if a clamp on type thermal couple device is available NOT! infrared. Clamp temperature device to the suction line pipe ( Large diameter large diameter ) going back to compressor. Record temperature.

    With this information there will be a less guessing and we might get somewhere make it much more easy.
     
  14. GreenTerrorPrius

    GreenTerrorPrius Junior Member

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    Wow, great info, but I cant really do this right now, I would need to study up on it or take it to a AC shop.
    I will follow up with more info when completed.
     
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