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Sls 2012 loses all power randomly on start up

Posted: Wed Mar 03, 2021 3:55 pm
by Kizzzy2weeks
:facepalm:

It's happened about 4 times in the past month. It's usually on a cold start.

I press start and the car loses all power, can't open the trunk even, the brake pedal goes stiff just nothing. There's no CELs on, it resets the A/B mileage also. Idk if it could be a relay or starter motor. It's got 135k miles. I was thinking the starter relay is going not sure. I'm also getting some extra grinding/whining during cold morning starts, it was louder last winter and I assumed it was from being low on oil all the time.

It comes back on by itself after a min or only after I open the hood then I hear all the gadgets turning on.
:facepalm:

Re: Sls 2012 loses all power randomly on start up

Posted: Thu Mar 04, 2021 12:42 am
by old tech
Try cleaning battery terminals first. That will be the most likely the cause. next in line would be ground cable connection. Lastly if those are found to be good, a battery internal problem. A free battery load test at the parts store may reveal the problem also.

Re: Sls 2012 loses all power randomly on start up

Posted: Fri Mar 05, 2021 6:55 pm
by KuroNekko
This sounds like a weak battery. Voltage test is in order.

Re: Sls 2012 loses all power randomly on start up

Posted: Sat Mar 06, 2021 12:38 am
by Kizzzy2weeks
:facepalm:

It was just loose positive connection and tray holder so it was just sliding around, everything clean though no corrosion. Starts fine now

:facepalm: