Random no power issue

[Hjoken]

I have a 2013 yaris hatchback (187k miles)I've been having a odd issue with. Every once in awhile when you come out to start it ,it will be completely dead power wise like the battery is disconnected. If you jump the car it starts right away and the issue will disappear for quite awhile. My wife uses it for work and on the way home stopped at target and it did it to her as well. I changed out the alternator last year thinking it might of been the issue. I tested the battery tonight and its showing 12.8v (on the terminals and the battery leads) and 14.2v at idle. I am thinking possible bad battery cell or possible cables? Figured I would ask instead of throwing parts at it.

Thanks in advance for any advice.

[Neinris]

I have a 2013 yaris hatchback (187k miles)I've been having a odd issue with. Every once in awhile when you come out to start it ,it will be completely dead power wise like the battery is disconnected. If you jump the car it starts right away and the issue will disappear for quite awhile. My wife uses it for work and on the way home stopped at target and it did it to her as well. I changed out the alternator last year thinking it might of been the issue. I tested the battery tonight and its showing 12.8v (on the terminals and the battery leads) and 14.2v at idle. I am thinking possible bad battery cell or possible cables? Figured I would ask instead of throwing parts at it.

Thanks in advance for any advice.

Hello! Does it still have the original battery? If so, then it's more likely needs to be replace. You could also bring it to a car parts store like Autozone and they can test your battery for you. If you're suspecting back cable, test the negative terminal with a multimeter to ground, it should not be more than 1 ohm, wiggle it around and see if there's any change, same thing with the positive to the alternator's positive output.

Good luck!

[Hjoken]

The battery is about 3 years old .I did have the battery and alternator tested and both came back fine.Im thinking a bad ground because of the total loss of power.Ive tested each day since it happened this last time with no unusual readings.

[zoidberg444]

Have you tested it when it actually acted up? Did you get a normal voltage reading from the battery (at least 12.5V) when it has been "dead" like this?

Before running to replace the battery I would suspect - if the battery was dead it has an intermittent parasitic draw somewhere - that could be a bit of a pain to diagnose.

The other thing is what circuits are dead? That could also be a clue. Does the head unit or the horn or the lights work when it does it? Or is it the final key position before start that nothing works like the dashboard, starter, fuel pump. etc

[Hjoken]

It always seems to happen not at home so testing isnt always the easiest. The car had been used all day with no issues. The wife was on the way home and stopped at Target. She came out and put the key in nothing. No lights,radio,and gauges,etc. A quick jump brings it right back and the issue disappears for a couple weeks/months. As soon as she got home I went out and tested it and got 12.8v on battery and 14.2 at idle.I tested it again the next morning and it was the same readings.