Sudden catastrophic power failure at 13 months 20,000 miles.

[ShadowsPapa]

His issues were very different from that. Not related.
My CANbus communication issues were the connector behind the glove box.

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[ShadowsPapa]

I assume it is a fuse associated with the fuse box. I just know what the dealership told me when I went to pick it up. The root cause is that, at some point, my negative battery cable came off the battery post. And the battery probably drained and/or the 'master fuse' fried.

The negative cable probably came off because I had disconnected and reconnected it so many times adding mods and just did a bad job re-connecting it. So it worked its way off the battery post.

This is the high current fuse array. I suppose if you want to call it a master.......... but it is responsible for the charging of the batteries and the EHPS and cooling fan, etc.

Here is what it handles -

 

[plumber802]

This happened to my wife's 23 JLUR with only 1500 miles on it. She has a short commute (1 mile each way) and the battery was not getting charged fully. I added a battery tender the she plugs in after work every day. I also added a battery tender to my JTM as cheap insurance.

 

[BearFootSam]

Not sure what he means by a "blown master fuse". All I can figure is one of the multiple legs of the high current fuse array blew. It's not something you carry a spare for unless you mess with and mess up your electrical system. it's not a unplug and plug back in. Not horrible to replace, but does take tools and care and it's cost is something getting close to $200 if I recall correctly - maybe closer to 175......
If he's referring to the high current fuse array - it's at the end of the fuse panel/PDC and it's where those multiple nuts on studs are (marked N2, N3 and so on) - that's one big fuse.

Not sure what is up yet, dealer isn’t supposed to look until tomorrow. They did eventually get me a loaner after a big stink but that it so far.

I have a winch and driving lamps but the latter is fused and wired via a relay off an accessory switch and was not on. I can’t conceive of any scenario in which these add one were a factor.

 

[BearFootSam]

Update: Dealer finally got to looking at the beast - Battery shows 12v but there is no power to the bus/data. So seems like battery and alternator are not the issue and there is a deeper electrical or control module failure. Given how these electrical gremlins go I am bracing for a repair that could take weeks. Bummer

 

[ShadowsPapa]

Update: Dealer finally got to looking at the beast - Battery shows 12v but there is no power to the bus/data. So seems like battery and alternator are not the issue and there is a deeper electrical or control module failure. Given how these electrical gremlins go I am bracing for a repair that could take weeks. Bummer

I hope you are generalizing when you say "Battery shows 12v" as that's a battery only about 50% if that.
A battery at 12 volts at rest can drop to almost nothing with any sort of a load on it.
Just ran into that with my garden tractor battery - read charged, 12.6 volts but the instant the key was turned on, it went down to nothing.

It shouldn't be difficult for them to find out why there's no power to anything - all of that resides in the PDC, where that high current fuse sits on the bus.

I have little faith in any mechanic - be it a dealership or a private/independent shop. They all scare me when it comes to electric work. They don't even understand the basics of electricity, Ohm's law or anything related.

 

[Hootbro]

I hope you are generalizing when you say "Battery shows 12v" as that's a battery only about 50% if that.
A battery at 12 volts at rest can drop to almost nothing with any sort of a load on it.
Just ran into that with my garden tractor battery - read charged, 12.6 volts but the instant the key was turned on, it went down to nothing.

Probably generalizing. 99.99% of people do not get into the red pubic hair of details like we do of stating battery voltage to the decimal point place when talking about whether there is battery voltage on a path.

 

[BearFootSam]

I hope you are generalizing when you say "Battery shows 12v" as that's a battery only about 50% if that.
A battery at 12 volts at rest can drop to almost nothing with any sort of a load on it.
Just ran into that with my garden tractor battery - read charged, 12.6 volts but the instant the key was turned on, it went down to nothing.

It shouldn't be difficult for them to find out why there's no power to anything - all of that resides in the PDC, where that high current fuse sits on the bus.

I have little faith in any mechanic - be it a dealership or a private/independent shop. They all scare me when it comes to electric work. They don't even understand the basics of electricity, Ohm's law or anything related.

Ok, got me, I was generalizing. The shop told my wife verbatim “the battery was at 12v so it’s not that”. I, perhaps in fault, assume that the dealership mechanic saying that means it’s actually at 12.6v or there about for the nominal “12v”. I know myself that the voltage during an ESS stop would read 12.5-12.6 which is expected for a lead acid battery. We take hour plus trips frequently, hence tolling 20k miles in 13 months, so the batteries should, “should”, be ok.

It should be a warranty issue, I just hope (1) it is resolved expeditiously & (2) they fix every primary and secondary issue the first go.
If my luck couldn’t be worse, my 2022 triumph threw a rod out of the blue this afternoon, fml.. All this and you would think I don’t know where the dipstick is but I am actually fastidious about my vehicles. The only other time I’ve had a breakdown in my 39 years on the planet was a land-rover (right?) that I fixed with a hose clamp and a knife in 5 minutes.

 

[ShadowsPapa]

If my luck couldn’t be worse, my 2022 triumph threw a rod out of the blue this afternoon, fml.. All this and you would think I don’t know where the dipstick is but I am actually fastidious about my vehicles. The only other time I’ve had a breakdown in my 39 years on the planet was a land-rover (right?) that I fixed with a hose clamp and a knife in 5 minutes.

OUCH!
Well, I hope your Jeep luck is better - and that you get the rear tech who knows positive from negative or how to read schematics.

 

[Pauliboy]

I had this exact thing happen to me here in Australia. The dealer had replaced the stop start battery. I drove 900kms and found the negative battery lead loose so tightened. Drove another 4ookm and had the same pull over warning lights on. Engine kept trying to start and just kept cranking then everything went blank. Checked under bonnet/hood and positive battery lead was totally loose. Thus battery would have been intermittently charging/not charging and spiking. Blew a main fuse. Temporary fix for now by the local dealer where we were at. Now awaiting a whole main fuse bank. PLEASE NOTE THIS WAS NOT THE DEALER THAT FITTED THE LOOSE BATTERY LEADS.

 

[ShadowsPapa]

I had this exact thing happen to me here in Australia. The dealer had replaced the stop start battery. I drove 900kms and found the negative battery lead loose so tightened. Drove another 4ookm and had the same pull over warning lights on. Engine kept trying to start and just kept cranking then everything went blank. Checked under bonnet/hood and positive battery lead was totally loose. Thus battery would have been intermittently charging/not charging and spiking. Blew a main fuse. Temporary fix for now by the local dealer where we were at. Now awaiting a whole main fuse bank.

This is where people need to see Tysongladiator's youtube video

https://www.jeepgladiatorforum.com/...-those-batteries-just-yet.74283/#post-1211885

He addresses that high current fuse array (the fuse to which you refer) and the loose connections at the battery terminals and more. Simple stuff that can pretty easily be checked, and he shows the parts and examples.

As often as people through loose connections like this, or owner themselves blowing the fuse by not understanding how cables should be removed and separated, you'd think dealers would have at least a couple of these on the shelf (both versions)
That same high current fuse array is used in Gladiator, Wrangler (JL/JLU) and the Wrangler 4xe - in other words, a huge chunk of the Jeeps out there use this thing. To not stock one is at the very least, interesting.

 

[Pauliboy]

And you would expect the dealer service to know how to attach/tighten a battery lead!!

 

[ShadowsPapa]

And you would expect the dealer service to know how to attach/tighten a battery lead!!

The problem is more that the part isn't designed to any sort of range of battery terminal dimensions.
Once it reaches a point, it's tight. The nut stops turning. The ends of the clamp make contact with each other, butunless they tug on it or actually try to twist it, it will appear they've done a good job. Although it feels tight, the wrench says it's tight, it's a poor fit on the post.
I sort of wonder if the battery terminal sizes have gone the route of toilet paper - same price, smaller rolls. That's just a musing, not fact or even "educated guess".
Modern cable clamps have very little range - or at least aren't made to work on terminals that are worn, have been cleaned or might be on the small size of "spec range".

Look at the range of post sizes these cable clamps can accommodate compared to those on the Jeep -

Jeep - nut tight and yet is it snug on the post?

 

[BearFootSam]

As of Friday, evening the dealer's report was - none of the techs could figure it out and are lost. Apparently their "award winning" chief tech has been assigned the case and is supposed to look at her today.

 

[ShadowsPapa]

As of Friday, evening the dealer's report was - none of the techs could figure it out and are lost. Apparently their "award winning" chief tech has been assigned the case and is supposed to look at her today.

So he got a 300 pin for bowling?
Just kidding.............
Hopefully, they'll figure it out - otherwise they can always contact STAR, but good luck with that, our service manager had trouble getting a response back.
I've heard that their upper level support, and the customer care people are extremely short-staffed and behind because they can't get qualified people.

The service manager where our Wrangler is actually told me he's got an open bay and said "maybe I should see if we can hire you especially since you have your own tools"
Yeah, but not the modern stuff needed.
If I was a few years younger it would have been a hell of a temptation.
I'd always wondered what things would be like had I not said "thanks but no thanks" to a job offer years ago.

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