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AC won't blow cold after disconnecting 12v battery

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by JakeRidesAgain, Aug 23, 2016.

  1. JakeRidesAgain

    JakeRidesAgain New Member

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    Okay, I'm trying to post a reply but it isn't letting me...let me see if this works.

    EDIT: THERE WE GO

    That's where I'm running into a problem with my troubleshooting process. As-is, I can't tell if the AC is even being commanded right now. I'm not sure if the button itself is bad, the climate control panel, or if there's a switch/relay somewhere that isn't doing what it's supposed to do.

    I did do a search today to see what switches might be hooked into the AC system and found one. It plugs into the AC line itself, and has a number of wires going into the passenger compartment. I wasn't sure if this was some sort of switch that might be involved in turning the AC on and off (I don't see how) or maybe contained a failsafe of some kind that kept the AC off when it's damaged.

    There's also the question of that fuse in the inverter itself, as posted above...I have no idea whether I should check that, and if I need to replace it, how I'd even do it.

    Ugh. This is bumming me out, especially since all this stems from me trying to fix a snapped lug stud.
     
  2. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    Just a little humour: I'm picturing Jake typing away, arms like Popeye, lol.

    One thing that really jumps out for me: that the light on the AC button is not turning on. Maybe figure out what's up with that?
     
  3. JakeRidesAgain

    JakeRidesAgain New Member

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    Exactly what I'm thinking. I'm tempted to replace the climate control panel just to see if there's something screwy in there, at least then I can rule it out. It's weird I'm not getting a light on the button OR an error code, but I don't know how reliable the climate error code system is.
     
  4. JC91006

    JC91006 Senior Member

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    Or possibly you disconnected the compressor by accident when doing the wheel thing on the passenger side
     
  5. JakeRidesAgain

    JakeRidesAgain New Member

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    Whoops, should have mentioned that. Had the wheel off on the driver side, so I wasn't even over there. I was following the same line of logic until I tracked down the location of the compressor.
     
  6. JC91006

    JC91006 Senior Member

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    Well all the electrical stuff and fuses are on the drivers side. But I can't see that as a problem
     
    #26 JC91006, Aug 25, 2016
    Last edited: Aug 25, 2016
  7. JakeRidesAgain

    JakeRidesAgain New Member

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    Yeah, me either. It's all protected by the mud guard that's up in there.

    Uploaded the wiring diagram for the AC system if anyone is interested in maybe taking a look and telling me where I might be skipping a step. At lunch, I'm going to go see if the compressor kicks on when I start the car, and then run it to the AutoZone down the street and have them run trouble codes. I'll update if anything comes of it.

    Question: Could this be a symptom of a bad AC pressure switch maybe? This website gave me that suggestion, but I wasn't sure if it was a valid route of investigation or not.
     
  8. DonDNH

    DonDNH Senior Member

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    These extra wires might go to temp sensors in the cabin. If a sensor is bad, maybe it is telling the AC controller that it is cool enough and to shut off the AC.
     
  9. JakeRidesAgain

    JakeRidesAgain New Member

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    SOLVED!

    Oh, man, is my face red.

    It was a freaking wire plug! The damn thing wasn't seated all the way in, and I'm assuming since I live around the worst speedbumps/roadhumps ever, it jiggled out.

    Plugged it in, started the car, and held down the AC button. It went cold INSTANTLY.

    THANK YOU GUYS FOR ALL YOUR HELP. I never would have figured this out without y'alls patience and input, this place was instrumental toward guiding me to the right place to look.
     
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  10. JC91006

    JC91006 Senior Member

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    this is on the compressor?
     
  11. DonDNH

    DonDNH Senior Member

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    That's really good news. Stay cool!
     
  12. JakeRidesAgain

    JakeRidesAgain New Member

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    Under the passenger side dash, where the blower is. It's stashed far to the passenger side, way up underneath the glove box. There's three plugs up there, a wide one and two shorter ones. The top shorter plug had pulled out at some point, I'm assuming it wasn't seated correctly during service, and I guess it had just enough of a connection that everything was hunky dory until I drove it around for a few miles.
     
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  13. JC91006

    JC91006 Senior Member

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    I'm glad you figured this out, maybe someone changed the AC cabin filter and somehow got that plug loose
     
  14. robertwa

    robertwa Junior Member

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    I'm having all of the same symptoms that JakeRidesAgain had. A/C worked perfectly before I changed the 12V battery. Now, the A/C light won't come on when the button is pressed.

    I took it to the dealership, and they said that the A/C system needed to be "reinitialized" and that I was low on Freon. They charged me $400 and the A/C was working when I left the lot. The A/C light stayed on and it blew cold. I went to work and parked for about 2 hours, and now the A/C light won't come back on at all and it blows hot.

    I checked the plugs that Jake described and they all seem fine. I really don't want to go back to the dealer because they tried to sell me $600 worth of extra stuff I didn't need and took twice as long to fix it as quoted. I was able to get a refund out of them, so that feels a little better. :)

    Does anyone know what the dealer did to "reinitialize" the A/C? Is that something I can do myself? Any other possible causes?
     
  15. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    That's the smoking gun, right?
     
  16. Rebound

    Rebound Senior Member

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    Dealers are supposed to warranty their repairs. You paid them $400 to fix your AC. They did not fix it.
     
  17. StarCaller

    StarCaller Senior Member

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    bring it back /
     
  18. robertwa

    robertwa Junior Member

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    Yes, when it worked, the a/c light came on. Now, nothing happens when you push the A/C button.
     
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  19. robertwa

    robertwa Junior Member

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    I got a refund from them already. I'm just wondering if anyone else knows what the did to reinitialize the a/c.

    I reread my invoice and it says "Reinitialized a/c system using Toyota scan tools." Are there any non-dealer shops that have the Toyota scan tools? I feel like all of my local dealers are just trying to rip me off.
     
  20. Rebound

    Rebound Senior Member

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    The scan tool is called TechStream. You can buy one from Toyota for a few thousand dollars, or you can buy the cable and software from guys on eBay for about $20, and use your own Windows laptop.

    I bought a beat up $100 laptop with 32-bit Windows 7, which made things easy. I think the 64-bit TechStream hacked version is available now as well.

    I never used TechStream for AC, but that's where you start.
     
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