Help Needed - Bad Aux Battery? Mystery Cable??

[whiterubicon]

OK - so I went out to drive the Jeep today and it wouldn't start. i saw the gear selector in Drive and realized when I got out in a hurry yesterday, I must have left it in Drive, therefore, leaving the accessory on. I obviously killed the battery. So, I jumped the Jeep and it started right away. I drove it around and I was able to start and stop just fine. Turned it off, left it off for hours and it started right back up. however, I am getting the @! error and it says "Start/Stop not working. Service Start/Stop system. I have unplugged the F42 fuse and disconnected the auxiliary negative cable, and the error still remains. Did I kill the aux battery? If I take the auz battery out and charge it can it be saved? The main battery and aux battery were just replaced a few months ago - I would hate to have to do it again. While driving, I am seeing 13.7 - 13.9 volts on the battery via the Jeep information.

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[whiterubicon]

OK - this is a little troubling. I just went out to make sure that I disconnected the right negative cable and as I was pulling - I came up with a cable that is not hooked up. I do have the aux batter negative disconnected from the battery, but I believe the cable end in the picture should be hooked up. I have not worked on the Jeep for months - and I believe the last people to actually work on it was the Jeep dealer because the N1 terminal went bad - does anyone know where this goes?

 

[dchemphill1]

I am not able to see the end of a cable in you picture. Before going to drastic measures can you put a trickle charger on the main and let it be for 24 hours. With everything as it should be both batteries will charge. More than likely they got run down to a point where they won't operate ESS when you left it in Park??

BTW just disconnecting the negative cable and pulling a fuse does not stop ESS...it will still function but will use the main battery. This is howany cars function...no AuX needed. My Subura operates that way. Good luck.

 

[whiterubicon]

Thank you. I am going to hook everything back up when I get back into town and try a trickle charger. Hoping that fixes it. I am concerned that cable has been unhooked since the Jeep dealership worked on it. I had my son-in-law take a picture of his and send it to me, I know where it goes now.

Thanks again.

 

[Badweissenbier]

That ground cable looks to be one that should hook to the stud on the fender right above the cable in your picture

 

[whiterubicon]

That ground cable looks to be one that should hook to the stud on the fender right above the cable in your picture

That is it. Do you know that cable is for?

 

[Badweissenbier]

Not specifically although it’s a big cable which tells me it’s carrying a lot of juice. I’m not near my Jeep where I could check unfortunately.

 

[whiterubicon]

OK - so I unhooked the battery and then re-attached the ground cable that the dealership neglected too. I then reinstalled fuse 42 and hooked the battery back up. The Jeep was a little hesitant to start at first, but it did and the @! error went away. I took it for a drive and it said that Start/Stop was unavailable battery charging. I then hooked it up to a trickle charger last night. This morning everything is working as it should.

Couple of questions -

1. Should I bring to the attention of the service manager at the dealership that his technician failed to reinstall everything correctly.
2. With the ground not being connected, how was I not getting an error previously?
3. My Jeep only gets driven on the weekend, as I have a work car, should I connect it to a trickle charger at least once a week?

Thanks -

 

[Badweissenbier]

In order:
I would,
You may not have used whatever function the wire grounds.
My Jeep was a weekend use vehicle and I never had to trickle charge. Ymmv

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