Dash lights not coming on (I know)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by TripleFlipBacon, Sep 27, 2021.

  1. TripleFlipBacon

    TripleFlipBacon New Member

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    Yes i know the combination meter and I know all the tricks to get my dash to come back on however nothing is working i just need to get them on.

    I tried the headlights brake pump holding down climate even unplugging the battery for 5 minutes but nothing has worked. I kept the dash on by leaving my back door slightly open for a long time (couple months) , but it got closed somehow.

    Is there any reason the battery method isn't working?


    The headlights on and hitting the brakes with the door open used to work, then i had to do that plus mash the lock/unlock button on my door to get it on (worked 50% of the time) THEN the success rate of that dropped dramatically to the point where I just started leaving my door partially open to keep it from turning the dash off.

    Also my 12v reads 13.9 in park and it went from 13.9/13.8 to 13.3 suddenly while driving then back to 13.9 in park.
     
    #1 TripleFlipBacon, Sep 27, 2021
    Last edited: Sep 27, 2021
  2. dolj

    dolj Senior Member

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    This is a known problem so the best idea would be to fix the CM. Here's a good thread (pinned to the top of this forum): Combination Meter Repair - DIY. Read the first two pages and then maybe skip to the last 3 or 4 to start with.
    The capacitor on the CM has finally degraded to the point of not working.

    NB, as you are a new member, your posts will be moderated until you have made 5 posts.
     
    #2 dolj, Sep 28, 2021
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  3. jerrymildred

    jerrymildred Senior Member

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    Welcome to PC. The sad part of the internet is that FUD seems to stick and people fall for it.

    There's a thread here that has a routine of headlights, brakes, doors, etc. that supposedly makes the combo meter work again, but it's simply a means of running down the 12V battery enough that the bad capacitor in the CM will do its job. It fixes nothing.

    The fix is to replace the bad cap. The info @dolj linked is just what you need. Taking apart the dash seems intimidating but it's really pretty easy. It's just a lot of steps. This video is linked in that thread and in others, but I'll save you having to find it.


    As for the voltages you saw, the readings you get from your "battery" in Park and Drive, or any time the car is "READY," is actually the reading of the 12V charging systems output just like with any car.
     
    #3 jerrymildred, Sep 28, 2021
  4. TripleFlipBacon

    TripleFlipBacon New Member

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    This has happened once before when my door got closed somehow but I got them to come back on 5 ish attempts later throughout the day ( I deliver food for my job) now its been 3 days trying every time i get in my car. I was hoping i wouldn't have to replace the combo meter but ill check it out
     
    #4 TripleFlipBacon, Sep 28, 2021
  5. ChapmanF

    ChapmanF Senior Member

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    If you know somebody with the skills to replace the bad capacitor in the combo meter, then you don't have to replace the combo meter.
     
    #5 ChapmanF, Sep 28, 2021
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