Help with batt aux batt wiring

[Puch]

So there’s been 2 occasions that someone has had to mess with my battery(s) on my JTS
1. When the shop installed my front locker. They also damaged some wires and paid for the dealership to fix it.
2. When the dealership fixed the wires that the shop damaged.
That being said, recently I removed the Aux batt and the F42 fuse. Everything has been working okay until yesterday. I lost all power, dead!
I started looking around and noticed the main batt + terminal was loose. I’m sure that’s my fault, I removed it while removing the aux batt. I tightened it and still nothing.
Then I noticed that N1 on the fuse box was loose and sparking while I was moving it. I tightened it up and all power was restored. That’s when I thought I remember N1 should be dead if no aux batt is installed.
Am I mistaken or is N1 where I should only see voltage from the aux batt not the main batt?

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[ShadowsPapa]

So there’s been 2 occasions that someone has had to mess with my battery(s) on my JTS
1. When the shop installed my front locker. They also damaged some wires and paid for the dealership to fix it.
2. When the dealership fixed the wires that the shop damaged.
That being said, recently I removed the Aux batt and the F42 fuse. Everything has been working okay until yesterday. I lost all power, dead!
I started looking around and noticed the main batt + terminal was loose. I’m sure that’s my fault, I removed it while removing the aux batt. I tightened it and still nothing.
Then I noticed that N1 on the fuse box was loose and sparking while I was moving it. I tightened it up and all power was restored. That’s when I thought I remember N1 should be dead if no aux batt is installed.
Am I mistaken or is N1 where I should only see voltage from the aux batt not the main batt?

No, N1 should be hot because the main/crank battery and aux battery were connected in parallel. That means that unless you remove all of the cables and PCR from the aux battery area, the main battery will still be connected to N1

Follow the dashed line from the crank battery + and it ends up at N1.

Too much bad info out there...................

If N1 was dead, no power, your truck would be dead, too! That's the truck's electronics, HVAC, cluster, radio and more.

With that fuse removed, the PCR can't open. In fact, it doesn't open anyway except during an ESS stop event. That means that the two battery positives, aux and crank, are always connected together. Main battery is always connected to N1 as is the aux battery. The PCR is normally closed so the two are connected together.

 

[Puch]

No, N1 should be hot because the main/crank battery and aux battery were connected in parallel. That means that unless you remove all of the cables and PCR from the aux battery area, the main battery will still be connected to N1

Follow the dashed line from the crank battery + and it ends up at N1.

Too much bad info out there...................

If N1 was dead, no power, your truck would be dead, too! That's the truck's electronics, HVAC, cluster, radio and more.

With that fuse removed, the PCR can't open. In fact, it doesn't open anyway except during an ESS stop event. That means that the two battery positives, aux and crank, are always connected together. Main battery is always connected to N1 as is the aux battery. The PCR is normally closed so the two are connected together.

Thanks for setting me straight. I’m trying to chase a problem with my front turn signals too (turn signals out warning, but they are working). Thinking my main power was wired incorrectly was really concerning me.

 

[ShadowsPapa]

Thanks for setting me straight. I’m trying to chase a problem with my front turn signals too (turn signals out warning, but they are working). Thinking my main power was wired incorrectly was really concerning me.

A bad connection can do some really weird, freaky things. So - what you did tightening things, finding poor connections may have fixed some issues or prevented it from throwing codes and lighting the dash up like a Christmas tree.

The reason some do the "pull fuse, disconnect aux battery" method is because it really leaves everything alone. It touches nothing else, doesn't require "rewiring" and won't cause any trouble with anything as long as all you did was remove the aux battery connection as instructed in Jerry's thread in this forum, or his info on the Wrangler forums.
He's all about doing things in ways that are simple and cause no future problems. He's looked at the wiring left, right, upside-down and inside-out.

Now that you've resolved the connections there - on to the turn signal issues!

There is actually a fault wire that leads from the turn signal "assemblies" - I'm in my shop and don't have access to the files and images on my server, but you may be looking at something as simple as a single wire or connection issue.
Have you made any changes to lighting, added any lighting, tapped into anything lighting related? (always a place to start with troubleshooting - "what changed" is the first question to ask.)

 

[Jaxmax]

“ What changed” is the most important troubleshooting task, right after “did you turn it on?”, and “What the hell were you thinking!”, after those first three steps is when it gets to real troubleshooting my electricians seldom get past number three at sites….Jack

 

[ShadowsPapa]

“ What changed” is the most important troubleshooting task, right after “did you turn it on?”, and “What the hell were you thinking!”, after those first three steps is when it gets to real troubleshooting my electricians seldom get past number three at sites….Jack

LOL - good one. The latter two I've used a lot in my interactions with others who have done "work" on things. Sometimes I got calls about network equipment and then #2 was king. And I hear "oops" on the phone in response.

Good one for you -
For a couple of years I worked as an electrician for Principal Financial Group. Our team was responsible for minor office moves, people shuffling, etc. and our counterpart, the "night crew" as they were affectionately called, did the major departmental moves involving a half dozen or more people or entire departments from floor to floor, building to building or even from 8th floor east to 8th floor west.
Came in one morning to see a lot of calls coming in and trouble tickets. Network down, phones not working, no power, you name it.
Besides bigger things, printers, copiers and such, both teams did the 120v and 220v wiring, phone moves and network connectivity.
Come to find out south half of 4th floor of the headquarters was moving to the north side where there was more space for expansion. The night crew moved all of the phone connections and network connections in the closet - on the 3rd floor. So not only was almost no one on the 3rd floor working, the 4th floor was down as well.
Paper trails are your friend, right? Just go put things back. Well.......... "we can't find the records and what we have is older" and of course the night crew was GONE for the day.
There's a reason why I was often asked to come in on major moves by myself, starting at 3 or 4 am and it wasn't just the sound of the core drill in the concrete floor. I was methodical and kept good notes.
Fact is, I recently found one of my notebooks from back then!
Anyway, with electric, be logical, methodical, take notes, take pictures if you need, interruptions happen, distractions happen. If you know how something should work, you can usually find and fix why it doesn't. The biggest monkey wrench in the works is when a human person has touched something. Natural breakdowns are easy, but when there's human hands involved - all bets are off.

 

[Lost1wing]

Power, ground, dyfwi, dsefwi or it is out in the elements. Those are my steps to troubleshooting. I'd start at the bulb and related connections. ​

 

[Puch]

A bad connection can do some really weird, freaky things. So - what you did tightening things, finding poor connections may have fixed some issues or prevented it from throwing codes and lighting the dash up like a Christmas tree.

The reason some do the "pull fuse, disconnect aux battery" method is because it really leaves everything alone. It touches nothing else, doesn't require "rewiring" and won't cause any trouble with anything as long as all you did was remove the aux battery connection as instructed in Jerry's thread in this forum, or his info on the Wrangler forums.
He's all about doing things in ways that are simple and cause no future problems. He's looked at the wiring left, right, upside-down and inside-out.

Now that you've resolved the connections there - on to the turn signal issues!

There is actually a fault wire that leads from the turn signal "assemblies" - I'm in my shop and don't have access to the files and images on my server, but you may be looking at something as simple as a single wire or connection issue.
Have you made any changes to lighting, added any lighting, tapped into anything lighting related? (always a place to start with troubleshooting - "what changed" is the first question to ask.)

Thanks for all the info. I haven’t gone to deep into trouble shooting the turn signals yet. Seems strange that both lights have the warning message. I’ll have to trace the wires and see where the common junction is.

 

[ShadowsPapa]

Thanks for all the info. I haven’t gone to deep into trouble shooting the turn signals yet. Seems strange that both lights have the warning message. I’ll have to trace the wires and see where the common junction is.

That is indeed weird.... sometimes grounds are common. Someone here has a "map" of ground points on these trucks. Maybe they'll jump in.

Power, ground, dyfwi, dsefwi or it is out in the elements. Those are my steps to troubleshooting. I'd start at the bulb and related connections. ​

Yes - but if I read his message correctly (if, I know, if) it's "turn signals" rather than one. Bulb - not as likely but grounds - they may be in common. I know the LED lights on these are voltage regulated so the chance of blowing multiple bulbs in these is pretty slim.
But we've seen where wiring harnesses have been burned or worn through, grounds have been bad and so on, so that "related connections" bit especially I'd jump on.

 

[mrmo]

So the PCR is strictly for the ESS? If you remove the Aux batt you can remove the PCR too? I have an invertor that I want to put into the space of the Aux batt after removal and run power to the bed.

 

[ShadowsPapa]

So the PCR is strictly for the ESS? If you remove the Aux batt you can remove the PCR too? I have an invertor that I want to put into the space of the Aux batt after removal and run power to the bed.

Yes - but keep in mind that you lower your reserve capacity if you remove the aux battery - meaning everything comes only from the main battery and you'll drop voltage more quickly.
Otherwise with the aux battery in place any load is able to draw from both batteries so you have a higher combined capacity.

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