LC randomly goes dead (no power to car) even with full main battery, also power window issue (1 Viewer)

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I have a 2016 and I can't figure out what's causing some electrical issues. A few months ago, I had my first experience with no main battery power. I went to unlock with remote and LC wasn't responding. Thought it was remote, so I unlocked car with key and no lights came on and car wouldn't start. So, thought I had a dead battery. Jumped it from the second battery and went to garage. But, I put a multimeter on it and everything was fine. When I hooked the vehicle wiring back to battery, everything went back to normal. Thought it was some sort of weird fluke, so I didn't investigate further.

Fast forward to today. I haven't driven the LC all week as I've been out of town. Come home and do a quick errand. LC started fine, but when I go out to car to return from store, the LC has no power. Complete loss of 12V power. Symptoms of a completely dead battery (or no battery hooked up at all). Jumped it and went back home to investigate. Same thing as before. Multimeter read 12.93V and I also hooked up a battery charger which read 98% (pictures attached). As happened before, when the vehicle wiring was hooked back up to battery, power was back to normal. Not sure what is causing this as the battery terminals are clean (picture attached) and were on tight.

As a side note, I found that all windows except the driver's side won't roll down. Also, the driver's side only rolls down while holding (no auto). I checked every low profile mini fuse in the engine bay and the two areas under driver's and passenger dash and I couldn't find any bad fuse.

Any ideas as to what might be causing the main power issue and the window issues? I don't know where else to look for possible causes. I haven't done any work, upgrades, etc. on the LC since end of last year. So, I can rule out anything related to work on the car recently.


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@grey200 had similar issues. Couple threads on it iirc. Not sure if he ever figured it out.
 
@grey200 had similar issues. Couple threads on it iirc. Not sure if he ever figured it out.

Thanks, I'll look around. I did find the thread below, so I'll check if it's related to the Slee terminals.




I found this thread regarding the windows. Maybe they just need to be calibrated after losing power? I'll try it tomorrow.

 
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Rodent damage?
 
Hey check the voltage at the part that connects the starter wire to the battery terminal, not the terminal itself. I had similar issues and turned out there was lots of corrosion, yet I couldn't see it, between the Slee aluminum extensions I was using and the terminal. I was reading full at the battery but at the starter cable only 5 volts. I'd jump from my 2nd battery and it would fire up because my second battery cable was basically touching the starter cable behind the main battery terminal. Also remove and clean the ground cable and where it connects to the body. Take apart all the connections at the main battery and use baking soda/water and scrub away and then put back together. Lastly, if you haven't already change the batteries in the key fob but this doesn't sound like that issue. Keep us posted.
 
This is turning into a knee jerk reaction but.. original windshield? Sure there are no leaks?

Beyond that, corrosion at the terminal and auto window needing to be calibrated is plausible.

@Mogwai point about checking the cable/terminal/cable end, not just the battery post itself, is key.
 
Rodent damage?

Don't think so. No signs of it.



Hey check the voltage at the part that connects the starter wire to the battery terminal, not the terminal itself. I had similar issues and turned out there was lots of corrosion, yet I couldn't see it, between the Slee aluminum extensions I was using and the terminal. I was reading full at the battery but at the starter cable only 5 volts. I'd jump from my 2nd battery and it would fire up because my second battery cable was basically touching the starter cable behind the main battery terminal. Also remove and clean the ground cable and where it connects to the body. Take apart all the connections at the main battery and use baking soda/water and scrub away and then put back together. Lastly, if you haven't already change the batteries in the key fob but this doesn't sound like that issue. Keep us posted.

Thank you, I'll take a look at that and clean everything up good. Seem like some of the people that have had this issue have the Slee battery tray and terminals. Wonder if that's the culprit.



This is turning into a knee jerk reaction but.. original windshield? Sure there are no leaks?

Beyond that, corrosion at the terminal and auto window needing to be calibrated is plausible.

@Mogwai point about checking the cable/terminal/cable end, not just the battery post itself, is key.

Yes, original windshield. No signs of any leaks. I'll take everything apart at the terminals, but it does seem fine. Can't see any visible corrosion.
 
My 2018 LC200 is in shop for same reasons: random episodes of complete vehicle shutdown solved by applying Genius Booster Lithium Battery which starts/resets vehicle and then sporadically resurfaces with complete electrical startup (including no key FOB commands) failure:(

The Dealer has affirmed that they are no 'basic' electrical connection issues, new battery (optima yellow 27F age) /alternator good, all codes good, diagnostics negative so they are now playing the multi-meter hunt/search tedious game.

Any resolution from the OP?
 
My 2018 LC200 is in shop for same reasons: random episodes of complete vehicle shutdown solved by applying Genius Booster Lithium Battery which starts/resets vehicle and then sporadically resurfaces with complete electrical startup (including no key FOB commands) failure:(

The Dealer has affirmed that they are no 'basic' electrical connection issues, new battery (optima yellow 27F age) /alternator good, all codes good, diagnostics negative so they are now playing the multi-meter hunt/search tedious game.

Any resolution from the OP?

My issue was with the aluminum Slee battery extensions arcing and eating away on the lead military terminals. I ended up getting new terminals and putting a brass washer between the extensions and the terminals. Do you have Slee extensions?

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My issue was with the aluminum Slee battery extensions arcing and eating away on the lead military terminals. I ended up getting new terminals and putting a brass washer between the extensions and the terminals. Do you have Slee extensions?

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@brasskey What do the brass washers do? I'll toss some in if they are good preventative maintenance.
 
I'm curious also. A third metal in the mix?
They prevent dielectric corrosion due to dissimilar metals. If you have an old house with galvanized pipes and want to plumb a new bathroom with copper you need a similar fitting (brass, typically)
 
Followup: Picked up 200 this am from Dealer after a week in shop of trying to find the Ghost in the Machine. No error codes, computer checked out ok, no chewed up wires, no electrical component recalls, multi-meter hunt negative, grounding wires all checked and were intact and tight, battery/alternator good, battery terminals with Slee Extensions taken apart and were fine. They started it and turned it off multiple times with no issue.... So sort of good news but still don't have a diagnosis.

Guess I will always have a Genius Booster in truck and carry a multimeter with me so I can try and figure it out if/when it happens again.
 
Followup: Picked up 200 this am from Dealer after a week in shop of trying to find the Ghost in the Machine. No error codes, computer checked out ok, no chewed up wires, no electrical component recalls, multi-meter hunt negative, grounding wires all checked and were intact and tight, battery/alternator good, battery terminals with Slee Extensions taken apart and were fine. They started it and turned it off multiple times with no issue.... So sort of good news but still don't have a diagnosis.

Guess I will always have a Genius Booster in truck and carry a multimeter with me so I can try and figure it out if/when it happens again.
Very disconcerting. Even if the Slee extensions looked fine, I'd still keep my eye on them as the culprit. Mine looked fine too, but they weren't until I took some baking soda and metal scrub brush to them. I'll prob do this once or twice a year as routine maintenance, and will add brass washers too.
 
Followup: Picked up 200 this am from Dealer after a week in shop of trying to find the Ghost in the Machine. No error codes, computer checked out ok, no chewed up wires, no electrical component recalls, multi-meter hunt negative, grounding wires all checked and were intact and tight, battery/alternator good, battery terminals with Slee Extensions taken apart and were fine. They started it and turned it off multiple times with no issue.... So sort of good news but still don't have a diagnosis.

Guess I will always have a Genius Booster in truck and carry a multimeter with me so I can try and figure it out if/when it happens again.

You need to visually inspect the lead terminals closely where they touch the aluminum extensions. The lead seems to be eaten up more than the aluminum on the Slee extensions. Make sure there’s no pitting like on the picture in my previous post because that still might be the issue.
 
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There seems to have been enough cases of these issues related to the Slee battery terminal extension that I would ditch them. There's a fundamental compatibility issues between the metal that it's composed of.

I'd switch them out and move on as this will continue to rear its head.

Not the prettiest as I used some old ring terminals floating around the garage, but here's an idea for simple extensions for the military type terminals.
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There seems to have been enough cases of these issues related to the Slee battery terminal extension that I would ditch them. There's a fundamental compatibility issues between the metal that it's composed of.

I'd switch them out and move on as this will continue to rear its head.

Not the prettiest as I used some old ring terminals floating around the garage, but here's an idea for simple extensions for the military type terminals.
View attachment 2394634
Ok you convinced me
 

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