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Battery dead (?) and Prius stuck in ACC mode (maybe?)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Hour of Gold, Nov 28, 2013.

  1. edthefox5

    edthefox5 Senior Member

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    I'm Crazy Ed,

    Fairly easy but you may not have the arm strength to wrangle that battery out of the hole or put the new one in. Not with out hurting yourself. Take it slow.
    Best place to get hurt is weekend warrior on a car using muscles you never use. Hurt myself so many times.
    Best to stretch it out real good first. Your back will get a good workout. Not worth it to hurt your back for weeks then have to chase a toddler.

    On the red assy (The Positive post) that sits on top of the battery on the side of that red assy is 2 cables. Those both "unclick" and are removable.
    On there tabs you just squeeze the connector tab together and they come out. If memory serves they both unclick. That allows you to unbolt that red assy after battery out of car.

    Now since the positive cables are removed you can remove the ground lead without any sparking.
    Place cloth over that red assy. Remove ground lead that goes to the chassis. The one on the back of the battery towards the back of the car. Remove the 10mm bolt on the car frame. Leave the post side connected. Tape the bare end of the wire.

    Remove the battery hold down bracket and the little silver box next to the battery. Box is only 2 bolts. I think the hold down bolts for that box (battery backup power for brakes) are different lengths so pay attention to where they went.

    Pull battery out of hole. May help you to get in trunk and kneel over battery hole while lifting. Lift it into trunk.

    After battery out of car unbolt negative side assy from battery but first look at the relationship of the negative connector on the neg post of the battery. Its position to the battery. The Yellowtop will be different as its a little tighter in there.
    It will go back in sideways pointing to the side of the car. Leave it off for now. Soon as you get the neg cable off the battery tape over the post. Unbolt the big red assy. Tape over the post. Both posts should be good and taped over to protect from sparks if anything gets across it while storing or transporting. Battery explosions are very bad.

    Clean up battery hole in trunk. Inspect trunk for corrosion with flashlight. Look at all bolt heads for corrosion. Lost of ground connections in there that if rusty will make you crazy with intermittent issues. Any questions take a good picture and post.

    Lightly sand down the connection point on the chassis where the ground lead bolts too to bare metal. Clean and apply grease to that area.

    Inspect new battery carefully for cracks and deformation of the case. A new Optima should be charged up before installing by using a battery charger. I assume you do not own one so lets proceed. Since you got it it in the mail you were unable to ask a counter guy to charge it.
    Should be ok.

    Lightly sand down both new battery posts. Not much just enough to expose shiny metal. Then clean off posts. Tape over negative post.

    Grease the pos post and install red assy. Install battery back in car. Leave 2 pos leads "Unclicked" for now. Put cloth over red assy.

    Remove neg post tape and install ground lead on battery and leave post side loose. Lightly tap down on the ground lead post connector to get it deeper on the post Sand down the ground lead eyelet connector to shiny metal. Clean and grease. Bolt that sanded & greased lead to the car chassis area previously sanded and greased. Cover that bolt connection in grease. The neg post side was loose so you can now move it around on the battery post to the best unstrained and easiet position on the post. Tighten it down.

    Install battery hold down bracket and vent tube. Install 2 pos leads by "clicking" them back into red assy. Re-install silver box.

    Done.

    When you first start the car it may throw every light on the dash. Just shut car off and re-start.
    All radio presets will be gone and just lower window's halfway and then put them back up.


    Good Luck.
     
  2. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    I can't go on YouTube here but, I searched "change Prius 12 volt battery" and the first video that comes up is the one I like the best.
     
  3. Hour of Gold

    Hour of Gold New Member

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    Thanks! You guys are very patient with such a bumbling newb. :)

    So far, so good on getting the old battery out; someone has changed it before, I can tell now. (Which, since it's a 2004, I guess that figures.)
     
  4. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Yer doing great!!!!. :)
     
  5. Hour of Gold

    Hour of Gold New Member

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    Thanks! I'm cautiously hopeful. And crossing my fingers that it doesn't start raining.
     
  6. Hour of Gold

    Hour of Gold New Member

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    IT WORKS!!! I sort of can't believe it! I love everybody right now. :)
     
    uart likes this.
  7. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Good job!!!!!!. Easy day. :)
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    The standing water is worrisome. Keep an eye on the area, hopefully you can find the source.
     
  9. uart

    uart Senior Member

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    Good work. It's not the easiest battery to change, but once you've done it once it's not too bad.

    BTW. I'm glad that it did turn out to be only the battery. :)