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Electrical problems with the A/C

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Duane That Prius Lover, Oct 25, 2017.

  1. Duane That Prius Lover

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    Hello Everyone,

    Long time reader, first time poster.

    i have a 2008 prius "Second Gen" and i am having some interesting problems. Please help me if you can.
    so, i have 145,000 miles on it and i love the car. here is what is going on:

    all of the warning lights on the dash came on. i used a friends code reader and found that the inverter pump needed replacing, so i replaced it. that got rid of the big red !, after that the A/C will turn on and off by itself, it will also turn on and off when you turn the headlights on and off. i have replaced the headlights "HID" bulbs for $145.00 i have also replaced the "MFD" because it was not working the touch screen, a/c still comes on and off by itself. when it comes on the dash light for the a/c blinks on and off. the controls on the steering wheel do not work most of the time. sometimes they do, the horn doesn't work ever but the other controls on the steering wheel seem to work just fine" Cruise control, radio, map, and information all work fine. if i am driving down the road at night the a/c will come on by itself and only blow hot air, i turn the headlights on and off and the a/c will turn off, then the headlights will turn off one at a time. turn the headlight on and off again and the lights come on and so does the a/c.

    i hope someone can help me, i love this car so much. i really want to keep it going.

    thank you for your time.
    duane
     
  2. bisco

    bisco cookie crumbler

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    welcome!
    how long have you owned her, and did she come with any problems?
     
  3. Duane That Prius Lover

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    hello Bisco,

    i bought the 2008 prius brand new.
    no problems at all when i bought it only 5 miles on it.
    in past i have had to replace both headlights two different times.
    had a few recalls on it that they did for free.
    one of them was the a/c compressor recalled and replaced free.
    replaced the inverter pump
    and that is about it other than oil changes and such.

    thank you
    duane
     
  4. bisco

    bisco cookie crumbler

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    if the horn doesn't work, you have to find out if it's the spiral cable, or something after that. if the headlight stalk goes through it (maybe not) that might be a clue. also, perhaps a loose connection behind the mfd?
     
  5. Duane That Prius Lover

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    can you recommend a good short tester for it.
     
  6. Duane That Prius Lover

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    p.s also the power outlet for cell phones and cigarette lighter on the dash goes in and out of power with the a/c
     
  7. bisco

    bisco cookie crumbler

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    no, i'm clueless. hopefully, someone with electrical knowledge will jump in here. all the best!(y)
     
  8. Duane That Prius Lover

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  9. valde3

    valde3 Senior Member

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    It’s probably easiest to diagnose it as a problem in power outlet(s). As there is almost certainly only one problem fixing the outlet will fix ac as well.

    Do bough outlets stop working or only the one? Measure the voltage at power outlet fuse(s) when the problem is present if the voltage is lost then you know that problem is before that point if not it’s after that point. With wiring diagram this type of fault finding is pretty easy as long as the problem is present when diagnosing.

    Starting with diagnosing the horn problem is another possibility but it may not be related as horn problem doesn’t come and go with other problems.
     
  10. edthefox5

    edthefox5 Senior Member

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    Was not aware there was ever a recall on the G2 AC Compressor.

    One of the first things that suffer from a bad hybrid battery is the ac system. It demands alot of power that the battery is not capable of providing.

    Whats the hybrid battery look like consumption wise? Going to purple real fast then charging back up real fast and the mileage is tanking?

    Florida is very very hard on the battery classically if you have not made any effort keeping the cabin cool and leaving the car out in the sun with no sun shade all its life. High cabin temps are stressful to the battery.

    Have you ever heard the rear battery cooling fan turn on high in the back seat?.
     
  11. Beachbummm

    Beachbummm Senior Member

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    from what you describe Id think the "clock spring" in the steering wheel is bad.. its under the airbag.. I had the same problem in a dodge caravan years ago.. the horn,cruise control, radio and ac controls all run through it. if your traction battery is getting weak the AC is the first thing the computer shuts off to save energy . also when it comes to the HID headlight you dont have to buy top of the line, I have gotten a year and a half (so far) out of a $15 set off e bay.. good luck
     
    #11 Beachbummm, Oct 25, 2017
    Last edited: Oct 25, 2017
  12. Rachel Damron

    Rachel Damron New Member

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    can you please share this recall info? I haven’t found this info anywhere