Strange battery & non-cranking problems - please help ??

[smallhagrid]

This is about our 2011 Outback.

We’ve had a very strange couple of days with it & now it is parked where the towing service put it - and will go no farther until it can be fixed somehow.

 Monday 11/14 it started & was used to get to work with zero problems - then after work its battery was suddenly too weak for it to crank.

(No interior lights or anything were left on during work time.)

 After having a co-worker offer a jump, it did crank over & start.

It got home OK (~20 miles) - and again had not enough juice to re-start.

 Oddly, the battery read 12.7V on the DVM...so it was put on to charge for ~3 hours with our 10A charger - after which it was still too weak & again still came up with 12.7V somehow.

 The next day that battery was totally flat - as if there had been something draining it all night.

 Later a spare, used battery was installed & it started right up with no problems & no trouble lights of any sort.

 Since that battery was years old & marginal at best the OB was driven ~45 minutes away to go buy a new battery - again - no problems indicated.

 Came out with the brand new battery - swapped it into the car - and that is when the troubles began...

 Attempting to start it had the dash lighting up normally, but when cranking was attempted all that was heard was a very quiet relay type sound seeming to be on the passenger side - but zero cranking.

(Sort of like what happens when cranking is attempted with just a plain steel, unchipped key...)

 Thinking the new battery was weak somehow, the booster pack was attached - same result.

 Swapped the old battery back in - no change.

 Our OB has the genuine Subaru remote starter - so the car was locked & that was tried - it made 3-4 attempts with just the same results & quit.

 Being totally baffled - the OBD reader was attached & showed 1 code, for CPS bank A as I recall.

 At that point, after trying what I could, AAA was called to tow it home.

 While waiting, I spoke with a friend who is a trained mechanic (though only seldom works on Subarus) & he said that to his knowledge there was no super secret decoder ring or other arcane stuff needed - just swap the batteries, and all SHOULD be well.

He also commented that most likely the CPS code should not have prevented it from cranking normally - whether it could then start, or not.

 At this point all the above has created concern & of course confusion as doing such a simple thing should have been just that - simple - but turned out so badly.

 Hopefully someone here can shed some light upon this situation before the OB has to be towed in for service.

 Thanks for any helpfuly replies !!

[Daskuppler]

My first thought would be a bad cable running to the starter or ground if the battery meters fine but doesn't crank could be luck that it started other times.

I would replace the positive cable running to the starter and the negative running to the alternator. If there's any corrosion anywhere, I would replace the terminals as well. Something like this is nearly indestructible but may be hard to use on the positive terminal depending on your setup: https://www.amazon.com/Ampper-Military-Battery-Terminal-Vehicles/dp/B07JJKVHD1

Maybe a bad relay?

Edited November 17, 2022 by Daskuppler

[heartless]

since things went from bad to worse with the battery changes, I would also suspect bad cables...

every time you changed the battery, the cables were moved, making any weak connections worse.

[forester2002s]

Try using jumper-cables to bypass the +ve cable from the +ve battery-post to the 12V input on the starter.

This can be tricky.  Wear safety-glasses, and connect the jumper-cable to the starter FIRST, and to the battery-post LAST.

Then try to start the car.

EDIT: Just had another thought - the 12V input on the starter is usually a stud on which is threaded a hex-nut.  If that hex-nut was loose, it might explain your symptoms.

Edited November 17, 2022 by forester2002s
New thought

[jonathan909]

13 hours ago, Daskuppler said:

My first thought would be a bad cable running to the starter or ground if the battery meters fine but doesn't crank could be luck that it started other times.

I would replace the positive cable running to the starter and the negative running to the alternator. If there's any corrosion anywhere, I would replace the terminals as well. Something like this is nearly indestructible but may be hard to use on the positive terminal depending on your setup: https://www.amazon.com/Ampper-Military-Battery-Terminal-Vehicles/dp/B07JJKVHD1

Based on the description and comments, I'd say "MIL SPEC my @ss" (like Ford trucks and their "military grade aluminum" - humph).  But they do look a little chunkier and more robust than the usual.

But yeah, most of the above suggestions cover it.  There's a very short high-current path between battery and starter and not that many parts to go wrong.  If it isn't the battery, it may be the starter (or just the solenoid), or a bad termination/connection between.  With a fully-charged new battery, do you see any voltage drop (at the battery) when you attempt cranking?  And do you see +12 at the starter's control input (from the starter relay) when you try to crank?

Edited November 17, 2022 by jonathan909

[Daskuppler]

3 hours ago, jonathan909 said:

Based on the description and comments, I'd say "MIL SPEC my @ss" (like Ford trucks and their "military grade aluminum" - humph).  But they do look a little chunkier and more robust than the usual.

But yeah, most of the above suggestions cover it.  There's a very short high-current path between battery and starter and not that many parts to go wrong.  If it isn't the battery, it may be the starter (or just the solenoid), or a bad termination/connection between.  With a fully-charged new battery, do you see any voltage drop (at the battery) when you attempt cranking?  And do you see +12 at the starter's control input (from the starter relay) when you try to crank?

I agree, they are far from military spec, but they work well and are beefy compared to the standard stuff. I run them on my Xterra and have an amp, light bar, and winch hooked up to one terminal. It's all clean and there are never power issues.

[smallhagrid]

Thanks for the great & helpful replies Folks !!

The situation here has gotten just a wee bit stranger IMO...

I walked down to the corner lot today (now that it isn't a lake anymore) & tried starting the OB - no change - so I lifted the hood & had a good look at the terminals & battery cables.

All still quite clean & tight - so I felt the cables up & down to check for any brittleness & found none - then just for the halibut - tried it again - here comes the punch line=>

It cranked right over & started right up !! Wow. Let it run a bit & came back to the house to see if I could find a spare battery terminal or 2, with no luck, sadly.

Until that all happened I was pretty much resigned to having it transported for service by our indie - but now I've ordered some good terminals (and spares) which should arrive 11/21 - at which time I'll change out the negative terminal & check it's cable for interior rot.

Since the other one is about 10x as sturdy it is my hope that it & it's cable remain OK...time will tell.

Sure does feel like having fallen into a DEEP rabbit hole !!

[lmdew]

Use LoadPro on you meter and load the circuit when you are taking voltage readings.

Yes you can load the circuit other ways, but most folks don't.  I've posted a few times with links to you tube.

[heartless]

13 hours ago, smallhagrid said:

All still quite clean & tight - so I felt the cables up & down to check for any brittleness & found none - then just for the halibut - tried it again - here comes the punch line=>

It cranked right over & started right up !! Wow. Let it run a bit & came back to the house to see if I could find a spare battery terminal or 2, with no luck, sadly.

probably not the terminals, but the cable itself..
best option is to replace the entire cable - that changes the terminals as well

[brus brother]

agree with Heartless. even if not "broken", corrosion can seep back up along the cable.

replace cable.

[Daskuppler]

It's likely the positive cable at the starter end.

[jonathan909]

15 hours ago, smallhagrid said:

Sure does feel like having fallen into a DEEP rabbit hole !!

I constantly amaze myself by finding the simplest answers to the problems that seemed so complicated and bewildering.

[brus brother]

16 minutes ago, jonathan909 said:

I constantly amaze myself by finding the simplest answers to the problems that seemed so complicated and bewildering.

Clip clopping sound is most likely a horse and not a zebra. (geographically dependent)

[smallhagrid]

Looked around some & made several calls for a + cable.

Seems like it is a generic one for the 2011 - any recommendations for a replacement, please ??

Thanks.

[Daskuppler]

41 minutes ago, smallhagrid said:

Looked around some & made several calls for a + cable.

Seems like it is a generic one for the 2011 - any recommendations for a replacement, please ??

Thanks.

Whatever the auto parts store has, cut to length, and crimp new ends or see what Subaru offers.

[smallhagrid]

It appears that the + terminal has 2 separate connections at the battery, 1 of which goes to the starter & both are bolted on - can you tell me if the cable to the starter is just a straight shot, as one would expect ??

(Those on the car are originals, still swaddled in the OEM coverings...)

[jonathan909]

Yup, it's the fat one, straight from the battery to the starter.  The other one branches over to the fuse box and powers the rest of the car.

 

[smallhagrid]

Thanks !!

So all I need to figure out is the correct length & pick up a #2 or #4 AWG cable - then figure out how to get that 2nd, smaller one connected.

Looks like tomorrow I'll be slicing off that swaddling...

[heartless]

57 minutes ago, smallhagrid said:

Thanks !!

So all I need to figure out is the correct length & pick up a #2 or #4 AWG cable - then figure out how to get that 2nd, smaller one connected.

Looks like tomorrow I'll be slicing off that swaddling...

take a good hard look at how the old cable is set up.. that will tell you all you need to know.

[GeneralDisorder]

We prefer to replace the terminals with similar-to-stock (Subaru does not sell the negative terminal except as part of it's sub-harness):

https://www.buyautosupply.com/products/k13101-toyota-gm-style-battery-terminal-kit-positive-negative.html

We cut off the factory Subaru crimped negative and crimp/heat shrink a lug to the cable for use with these terminals from BAS. 

These retain the stock look and feel and 10mm tooling of the OEM terminals. 

Use of quality terminals, some form of protectant (grease, spray, etc), and NOT torqueing them till you break the plastic around the terminal and cause the battery to leak are key to success here. 

GD

[forester2002s]

14 hours ago, heartless said:

take a good hard look at how the old cable is set up.. that will tell you all you need to know.

Yes, and take photos before you take it apart

[jonathan909]

13 hours ago, GeneralDisorder said:

We prefer to replace the terminals with similar-to-stock (Subaru does not sell the negative terminal except as part of it's sub-harness):

https://www.buyautosupply.com/products/k13101-toyota-gm-style-battery-terminal-kit-positive-negative.html

We cut off the factory Subaru crimped negative and crimp/heat shrink a lug to the cable for use with these terminals from BAS. 

These retain the stock look and feel and 10mm tooling of the OEM terminals. 

Use of quality terminals, some form of protectant (grease, spray, etc), and NOT torqueing them till you break the plastic around the terminal and cause the battery to leak are key to success here.

Thanks for the pointer to BAS and mentioning the tooling.  PO had replaced the battery terminal on our Forester with the usual parts-store lead clamp - with the 1/2" nut - and that annoyed the crap out of me until I replaced it with a junkyard harness to restore it to 10mm.