1. Attachments are working again! Check out this thread for more details and to report any other bugs.

3rd Gen Prius with water under 12v battery

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by EvenVeganSteven, Jul 20, 2019.

Tags:
  1. EvenVeganSteven

    EvenVeganSteven New Member

    Joined:
    Jul 20, 2019
    4
    3
    0
    Location:
    Louisiana
    Vehicle:
    2010 Prius
    Model:
    One
    Hey all, I am a new member but I have read through many threads to figure out some things about my 3rd gen. Recently my 12v battery died at an airport parking lot (of course one of the worst places for that to happen) and I realized that there was water in the spare tire well and by the 12v battery. I've read many threads about this with the 2nd gen prius but not the 3rd gen. Any thoughts on where it might be coming from? Has this happened to any other 3rd gen owners? It really builds up after some heavy rain (being in Southern Louisiana Barry put some rain in my car). I plan on doing some water tests soon but if someone else has fixed this maybe I'll know where to start.

    On a separate note, I have had a mouse in my car a few times and have had to remove the nest under the spare tire when it's dry. Any tips on preventing mice from getting inside?
     
    #1 EvenVeganSteven, Jul 20, 2019
  2. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    2,642
    1,134
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    Yes indeed! I had a similar situation a few months ago. I believe there was at least one thread about it, and I found a video of how to fix that problem. You have to remove the taillight assembly and clean out the half-rotted leaves, etc. clogging the drainage path which inexplicably is routed between the body shell and the taillight.

    Problem solved, until it clogs again.
     
    #2 CR94, Jul 20, 2019
    nicoj36, neosoul and EvenVeganSteven like this.
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,762
    48,974
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    welcome!

    also, the rain rail under the black plastic trim can be cracked, the hatch hinges can leak, or the hatch gasket can be bad.

    mice: major problem that needs to be dealt with before they chew your wiring and cause thousands of dollars in damage or even total your car.
    there are many threads here, just try searching google and click on gen3 priuschat hits. lots of advice on keeping them out, but it aint easy.

    all the best!(y)
     
    #3 bisco, Jul 21, 2019
    EvenVeganSteven likes this.
  4. EvenVeganSteven

    EvenVeganSteven New Member

    Joined:
    Jul 20, 2019
    4
    3
    0
    Location:
    Louisiana
    Vehicle:
    2010 Prius
    Model:
    One
    This worked for the most part. I cleaned out the leaves and sure enough, after a good rain here my battery area didn't have any more water. The other side has a little bit of water so i pulled the drain plug until I can figure out how the little bit of water got there.

    As far as the mice problem, when removed my bumper to get to the taillights I found a mouse nest on top of the metal bumper and figured that he was getting in through the exhaust flaps on either side of the car. I fabricated a metal cage around it so hopefully that solves that problem.
     
    #4 EvenVeganSteven, Jul 23, 2019
    neosoul and bisco like this.
  5. EvenVeganSteven

    EvenVeganSteven New Member

    Joined:
    Jul 20, 2019
    4
    3
    0
    Location:
    Louisiana
    Vehicle:
    2010 Prius
    Model:
    One
    Here are a few photos of this repair:
    20190722_184625.jpg Where the leaves were that needed to be cleaned out.

    20190722_184639.jpg Where I found the mouse nest in my bumper

    20190722_184612.jpg My overkill way of keeping the mouse from getting inside my Prius

    20190723_114634.jpg My current place that is leaking. If you look closely you can see the drop of water heading for my battery! Yikes!

    I'll update once I fix this so anyone else having this issue can get this resolved.
     
    #5 EvenVeganSteven, Jul 23, 2019
    bisco likes this.
  6. EvenVeganSteven

    EvenVeganSteven New Member

    Joined:
    Jul 20, 2019
    4
    3
    0
    Location:
    Louisiana
    Vehicle:
    2010 Prius
    Model:
    One
    Update: So I recently installed a back up camera in my prius right before this happened and I guess I was a little rough with one of the connecting rubber pieces that house wires from the hatch to the car. It didn't go back in all the way which let water in so I used some flex tape to fix it. Should hold up just fine now. To anyone putting in a reverse camera, be gentle with the connecting rubber pieces if you don't want a leak like me!
     
    #6 EvenVeganSteven, Jul 25, 2019
  7. neosoul

    neosoul New Member

    Joined:
    Oct 18, 2021
    1
    0
    0
    Location:
    Boston
    Vehicle:
    2010 Prius
    Model:
    Four
    Hi - I got the same problem for my 2010 3rd gen Prius. I couldn’t tell from the pictures where you cleaned the leaf. Was that black part behind the tail light (assuming passenger side). Thanks in advance!
     
    #7 neosoul, Oct 19, 2021
  8. whataboutbob

    whataboutbob Junior Member

    Joined:
    Jan 1, 2014
    72
    15
    0
    Vehicle:
    2010 Prius
    Model:
    IV
    can you share the link to the video? Thanks.
     
    #8 whataboutbob, Apr 21, 2023
  9. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    2,642
    1,134
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    Four years later, I don't remember where I found it. Probably in this site. You don't really need the video, anyway. Disconnecting the electrical connector and releasing all the fasteners are the tricky parts. You may have to remove the fuzzy trim panel that makes access awkward.
     
    #9 CR94, Apr 21, 2023
    whataboutbob likes this.
(You must log in or sign up to post here.)