A/C not working after being unplugged

Discussion in 'Gen 2 Prius Technical Discussion' started by Tekdeus, Apr 23, 2015.

  1. Tekdeus

    Tekdeus Shifted to Green

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    Hi folks, I had my A/C compressor unplugged over the winter, and now that I've plugged it back in, the A/C is not blowing cold. Is there some kind of programming reset that needs to be done? Any insight would be greatly appreciated, thanks:
     
  2. JC91006

    JC91006 Senior Member

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    There may be a leak in your system. Since it's pressurized, it could leak even if disconnected.
     
  3. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Is there some reason it was unplugged? My first thought: AC needs to be run perdiodically, to circulate oil in the system, to prevent seals from drying out/distorting/leaking. Considering the age, maybe this tipped it over the edge, started a leak.

    There should be a sight glass on one of the lines: a well charged system will shows just a few bubbles flowing as the system runs, then a crescendo of bubbles at the moment it shuts down. If it shows a lot of bubbles, constantly, not good. If it shows nothing, it could mean you're looking at air.
     
  4. valde3

    valde3 Senior Member

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    Yes it says that in many places. But AC doesn’t run in below freezing temperatures so it’s not used in winter anyways.

    And Prius (except gen1) doesn’t have compressor front seal that is the only seal in the AC-system that seals against moving part. It doesn’t have any other seal that seals against moving part either. They designed the system to be sealed with electric motor being in the AC-coolant, that’s why the system needs the special lubricating oil.

    Of course system being sealed doesn’t stop coolant leaks but it should make them smaller or less likely. And minimize the problems caused by not using the system for long time.
     
  5. JC91006

    JC91006 Senior Member

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    Thanks for offering your solution to this problem.....NOT.

    But interesting to know people unplug their AC. cool.
     
  6. valde3

    valde3 Senior Member

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    You can see the part of the Mendel Leisk post that I replied to. It above my message.
     
  7. JC91006

    JC91006 Senior Member

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    Yes I know you were answering his question. I was poking fun at your last comment.......it leaks but it's designed not to leak thingy......
     
  8. valde3

    valde3 Senior Member

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    Then you missed my main point. Because system doesn’t have any seals that seal against moving parts, not using AC for some time isn’t as bad for it as in traditional system.

    But back to original topic:
    Low AC-coolant pressure will give you the fault code (B1423). So if you read fault codes or get them read you will find the problem. If you get them read you need the place that can read Toyota hybrid specific codes. Of course it can be some other fault but it should give you code as well.
     
  9. JC91006

    JC91006 Senior Member

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    So basically if he didn't somehow damage his system, it shouldn't leak. Maybe he ran over some crusty roadkill and damaged a part.
     
  10. valde3

    valde3 Senior Member

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    Basically. But still very small leakage is normal. Normal leakage is just smaller than in traditional system. But unless you can clearly see the problem I would start by reading the codes.
     
  11. JC91006

    JC91006 Senior Member

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    to the OP, I would check your front radiator area, make sure you didn't run over anything and damage something there......then see if there's any codes that would tell you of a leak/low pressure.
     
  12. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Well in our "winter" the temp's typically still stay above freezing, daytime highs of 4~6C. We do occasionally get freezing temps, and very sporadically some snow, but the main weather in winter is rain. And then AC comes in handy, for dispelling window fog-up.
     
  13. Tekdeus

    Tekdeus Shifted to Green

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    The A/C was perfectly reliable before it was unplugged, so I'm guessing it may have thrown an error code when the ECU saw it was not connected, and perhaps needs the codes cleared or reset. Would disconnecting the battery clear the codes and possibly get it working once again? Thanks guys
     
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  14. bisco

    bisco cookie crumbler

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    sometimes it works, sometimes not. worth a try. if not, you'll need to find someone with a scanner.
     
  15. JC91006

    JC91006 Senior Member

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    to reset the car, just disconnect the battery negative for a few seconds.
     
  16. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Or maybe similar to loose gas cap: a few days driving will shut light off.

    But wait a sec: wasn't AC also not blowing cold? Or false alarm?
     
  17. Jon Hagen

    Jon Hagen Active Member

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    Do not unplug the AC compressor in winter. If you use the Defrost setting in the heater controls, the AC compressor must run to de humidify the defrost air.
    Allowing it to run, also keeps all the "through the compressor case" seals Like the electrical contact pins, coated with oil to prevent leaks. Same thing goes for any O ring seals in the AC plumbing.
     
  18. Mendel Leisk

    Mendel Leisk Sand Pounder

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    The car also calls on AC sporadically if you have mode set to Heat/Defogger. Even if AC button is off.
     
  19. Patrick Wong

    Patrick Wong DIY Enthusiast

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    There is no programming reset, but you can try to disconnect the 12V battery for a few minutes, for fun.

    Why would you "unplug" the compressor, and what exactly was unplugged? If you don't want to use the AC compressor for whatever reason, just keep the AC button turned off.
     
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