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2005 gen 2 prius won't start

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Mohamed Maark, Oct 17, 2021.

  1. Mohamed Maark

    Mohamed Maark New Member

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    Base
    I have a 2005 gen 2 prius, no check engine light or anything on. 12v battery is reading 13.9v. Once I press the power button inside the car the car completely dies, nothing works at all as if the 12v battery is non existent. I can then jump start the car and it will run again, until I press the power button it will go completely dead. Checked the 100a fuse visually and with a multi meter looks good. What's going on any ideas? Also when I turn off the car, and its dead, I check the voltage up front under the hood and it then reads only about 3v
     
  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    How many hours per week are you driving, and when was the 12v battery last replaced?

    Try checking the connections from the battery, including the ground strap the connects the negative at the chassis for corrosion.

    FYI : your posts are being moderated until you've posted 5 times.
     
    JC91006 likes this.
  3. JC91006

    JC91006 Senior Member

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    I think if you replace the 12v battery, your car will go back to normal. Measuring 3v up front means it's deader than dead
     
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  4. Mohamed Maark

    Mohamed Maark New Member

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    I drive my car ALOT because I use it for work. I checked the connections nothing seemed off or corroded. Again when u get the car running its reading 13.9v, but then once I turn it off, it reads 3sh volts instantly and this is up front not in the back. I don't think the battery is bad but for some reason the voltage is dropping significantly once I power off the car. Something has to be blown I think. There's no way the battery is dropping 10+ volts in a matter of a second once I press the power button. Something else isn't working properly. Again measurement for voltage is taken up front under the hood.
     
    #4 Mohamed Maark, Oct 17, 2021
    Last edited: Oct 17, 2021
  5. SFO

    SFO Senior Member

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    How long have you owned this vehicle?
    Yes, when the vehicle is charging the voltage will read around 13.9v, but as mentioned above your blown battery measures 3v when sitting.
    12v batteries don't last forever, and since you don't recall when the 12v was last replaced, best to remove the battery from the vehicle and take it to an auto parts chain that can offer a free battery test and or a low amperage charge.

    Some examples might include; oreillys, autozone, pepboys, napa, advanced auto (or whatever they're called now), etc.

    Have you checked for a parasitic drain while the vehicle is off?
     
  6. Mohamed Maark

    Mohamed Maark New Member

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    Thank you for all the responses. I have found the issue, it was due to a loose connection, was a bit hard to find but I found it.


    Thank you
     
    SFO likes this.