intermittent dead electrical system - how to troubleshoot?

My 2013 JK 2 dr generally runs fine and has plenty of battery. This morning I pulled the Jeep into the spray car wash bay and turned it off. Then I decided to reposition it, but when I went to start it, the electrical system was completely dead: no dash lights, interior lights .... nothing. Turning the ignition switch several times did nothing. I opened the hood, looked, didn't see anything wrong, closed it, and went back to try starting again. Now I saw the driver side "door ajar" indicator light, and the Jeep started fine. All was normal except the radio: that needed set up (as if it had been reset). The system was completely dead for a few minutes max.

Yesterday morning, as I was leaving my house to go wheeling, I noticed that all of the NAV data in my radio had been erased, and my cell phone was no longer paired. I think this is related.

Besides radio resets, and this sudden and temporary dead system problem, the Jeep has been running great.

What I've done:
* All of the battery connections feel solid and look good. The area is dry, a kinda dusty, and there is no corrosion or grease.
* I tried getting DTC codes, but the "turn key off to on 3 times" procedure didn't work.
* I opened the fuse box, and it looked like a bunch of colored blocks (like pictures I found on the internet). Dry and the slightest bit of dust present.
* I read the owner's manual where it lists the fuses, but I didn't see any with wording like "main fuse".

I'm stumped. What might I try to troubleshoot this problem? Will getting a volt/ohm meter help? If so, what should I check?

Did you check the cable connections at just the battery? It almost sounds like a bad/loose ground maybe where the ground connects to the frame just based on how it resets your radio almost as if you were disconnecting the battery...Has it ever died while you were moving or does it just not start up sometimes?

BobV said:

Did you check the cable connections at just the battery? It almost sounds like a bad/loose ground maybe where the ground connects to the frame just based on how it resets your radio almost as if you were disconnecting the battery...Has it ever died while you were moving or does it just not start up sometimes?

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I checked the battery connections themselves first. Solid, no corrosion. I couldn't tell where the ground connection is made. There are 3 (IIRC) thick black wires attached to the negative terminal, but they run off to places unknown (to me).

Has it ever died while moving? Yes, but that turned out to be a loose OBD connector that the Bully Dog chipset is plugged into. When it was loose, all kinds of weird stuff happened. Since it's been fine until this weekend. It has only not started once, but the radio reset the day before, so I suspect a new problem is brewing.

Sounds like your vehicle rebooted. If it was me, I'd just take it over to a dealership and let them take a look at it. No sense having a 13 with issues and if you have further issues in the future it would be documented. That's what I'm dealing with currently with a engine issue.

I got bad vibes talking to my dealer (read from a script types), and then I read what Voodo Actual went through with those folks.

http://wayalife.com/showthread.php?11985-A-little-help

No thanks.

I've been taking my Jeep to Olympic 4x4 Supply in Snohomish; they're independent, so they don't have Chrysler's secrets, but they are straight up. I'll ask them when they open next week.

On the other hand, I'd really like to know what I might do to troubleshoot this. Suppose it had happened while on the trail yesterday? What then?

This is gonna sound dumb, but how long after you put your fenders on did you start having problems? I remembera thread where people drilling holes for their mc fenders and hitting wires. Maybe a short?

I went through a similar situation on Monday and Tuesday of last week with my 2008! Very odd behavior that left me very uncomfortable driving my Jeep. When it first happened, I was at home so I grabbed my voltmeter to see how much juice was in the battery. I was at 12.4 volts, so I knew there had to be a problem with the cables or terminals. I removed and cleaned the terminals and the Jeep started fine. Got me to work, but then failed to start again at the end of the day. After disconnecting and reconnecting the terminals at the office, I was able to drive the Jeep and run a couple of errands that required parking and re-starting the Jeep.

I got home Monday night and installed a spare TIPM that I bought on Ebay, assuming that was the problem. Unfortunately that did not solve the problem either and seemed to make it worse, so I re-installed my factory TIPM. After re-installing the factory TIPM, I decided to leave the negative cable off overnight. The next morning I reconnected it; the Jeep started fine, so I drove it directly to the dealer. They kept it from Tuesday until Friday, and shockingly it never once failed to start for them.

In an overabundance of caution, I purchased a complete new Mopar battery wiring harness and I installed it Friday night. The Jeep hasn't failed me since the initial incidents. In my case, I think it was a bad terminal or cable. The battery had the power, but it just wasn't getting to where it needed to be.

@olram30, The fenders have been on for months, so I doubt this is the cause, but I'll mention it when I take the jeep into Oly 4x4 this week (getting RCV axles, and Currie drag link and tie rod).

@txjeeplover, Thanks for sharing your experience. I hope you don't mind some questions.

txjeeplover said:

... I removed and cleaned the terminals and the Jeep started fine. Got me to work, but then failed to start again at the end of the day. After disconnecting and reconnecting the terminals at the office, I was able to drive the Jeep ...

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These terminals? Sorry, but I am not familiar with my Jeep, so I need to ask.

txjeeplover said:

... After re-installing the factory TIPM, I decided to leave the negative cable off overnight. The next morning I reconnected it; the Jeep started fine, so I drove it directly to the dealer. They kept it from Tuesday until Friday, and shockingly it never once failed to start for them.

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That's a big reason I don't take mine into the dealer. I got the feeling they'd go by the book, fail to find anything, charge me, and the problem would remain.

The negative cable you left off. Was that at the TIPM, or battery?

txjeeplover said:

... In an overabundance of caution, I purchased a complete new Mopar battery wiring harness and I installed it Friday night. The Jeep hasn't failed me since the initial incidents. In my case, I think it was a bad terminal or cable. The battery had the power, but it just wasn't getting to where it needed to be.

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This is really interesting. If it's not difficult, can you explain where this harness is located, and what it connects together? Part of my problem is not knowing where wires are supposed to go.

Like this. It's located just beside and at the bottom of the fuse box. I have no idea what it is, but I wonder if it's something I should know about.



I'd love to get links to good videos showing things like removing the fuse box and replacing the battery wiring harness like txjeeplover did.

Edit: looks like an extra image volunteered itself, don't know how to remove it.

Many thanks all for your comments. I was going crazy trying to figure this out. While at the shop, I told the mechanic what I knew. He then pulled the battery terminal in a different direction than I had earlier, but he got it to move. !!! :doh: Wish I had pulled it that way. And, thanks to txjeeplover, I asked the mechanic to show me what the battery wiring harness is. The mechanic showed me, and also explained where some of the other cables went (winch and compressor). Problem almost certainly fixed, and I learned some things; pretty good.