Hello all,

I have an issue on my 2013 XJL 3.0 AWD. When it's dark out and I get in my car and turn it on- no more then 10-20 seconds later the whole electrical system starts to flicker on and off. The dashboard, headlights and everything else acts erratic for about a solid 5-8 seconds. After this happens the car returns to normal until I stop the car and turn it off. A few things to mention to help diagnose the problem...

1. This doesn't happen when it's cold out 99%. The yellow snowflake appears and the eco system automatically disengages.
2. 6 months ago I took it to the dealership to have daytime running lights activated (rigged car to do this). The headlights go on when I put the car in gear. I don't think this is a factor since this was an issue before.
3. This happens 99% at night. It does happen at daytime when I take a longer trip 1hr or more, same thing happens for about 5 seconds, I think the car is going to die, but it doesn't.
4. It happens once and then it doesn't happen again until I park and turn the car off. When I turn the car on again it can repeat the same flickering (80% chance).
5. Without the dealership diagnosing the issue, but by me mentioning all the factors stated above and below, they think it's the transfer box between the 2 batteries (another car had the same issue). This is a shot in the dark though.
6. Changing the lights to on, auto, or fog lights doesn't seem to have an effect on the issue.
7. I read about coils going bad, does this seem like that might be the issue?
8. The flickering happens if I stay in park, or if I decide to drive. It's more a matter of when and not if it's going to happen.
9. The main battery is relatively new (5mo old).
10. I do have a usb (music) in center console and one of the back cigarette lighters is occupied to power my dash cam (only activates when car is turned on).

Any suggestions would be much appreciated. Based on your input I would suggest to the mechanic to look at specific items first to keep maintenance costs down (time it takes to diagnose the problem).

'Thank You' in advance.

 

I had a similar issue but a little different. Maybe my experience will be pertinent.

My headlights and dash lighting flashed at night when I had my headlights on. It initially did it in auto headlight mode only, then eventually (over couple days) in all headlight modes. I changed out the headlight stalk for a new one and it fixed the problem.

Perhaps your issue isn’t the headlight stalk like mine, but it does suggest the dash lights and headlights are controlled together by the stalk. So if you have a problem with one, you could have a problem with both.

Others have had an issue with their daylight sensor (sorry if I’m naming the part incorrectly), where the car shifts between thinking it’s daytime and nighttime. I recall similar flashing symptoms being reported.

 

Thanks Nedoerr. I will look into your suggestion.

 

I had this issue back in late 2017. I didnt capture exactly when it would happen. It would just be random, usually at night though. The whole dash would go crazy, lights would flicker for about 5 to 10 seconds. Litterally every light on the dash flicker, then everything would work fine again.

The fix is in the small auxillery battery converter module located in the trunk on the right side behind the trunk liner. I found a newly used one on eBay for about $50, and I NEVER had that issue again. You can do it yourself without a dealer. Unscrew the 2 screws disconnect the connector, swap aux battery, reconnect the connector, screw in place, done.

 

Here's exactly what you need.

 

Thank you!. I just bought it off EBAY. This was the dealerships first and only potential fix (w/o looking at the car). It makes sense that you and the dealership mentioned the same thing. Worst case scenario is I'm out $41.00 .

Fingers crossed*

 

That should do it. That issue started to occur when I improperly removed the battery maintainer several times. I didn’t know that I was doing it incorrectly. Consequently, the above mentioned part was being damaged causing that flickering lights fault.

 

Did you have to disconnect the battery before installing?

 

Yes. I did.

 

How do you remove the battery maintainer incorrectly?
I don't want to cause troubles and I have a working SDD due to your fine help.
So I have been using the large DC power supply. I just unplug it? No problems yet?
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Happy holidays man! When I first started using SDD, I purchased a battery maintainer. Shortly after, I realized that a battery maintainer/tender wasn’t sufficient enough to keep the battery at the required voltage for programming. I later purchased an actual battery charger.

You can incorrectly remove the battery charger by disconnecting it from the terminals while the vehicle is in key position 2. The battery charger should ONLY be connected or removed when the vehicle is in the off position. I also mistakely turned the vehicle on while the charger was connected. 🤦🏿‍♂️ Long story short, this improper usage of the battery charger caused the whole “flickering dash lights” problem. Lesson learned. It didn’t occur right away, but it randomly occurred at different times while the vehicle was in operation. Hopefully, it never occurs to you. Don’t skip steps when using a battery charger; spikes in voltage can easily damage modules throughout the vehicle.

 

Well I have already started the car several times with the maintainer hooked up?
So maybe I have already caused problems?

Yes I finally bit the bullet and now have a 13.4 VDC 55 Amp maintainer.
If you start measuring amps it's surprising how much the car draws with the key on and how much extra it draws when using the SDD system.

But I have always connected/disconnected the maintainer with the car in the off position.
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Quite possibly. I did it once and the interior lights went haywire. Lol. The electrical components on the XJ can be very problematic. That’s why there’s so many posts on here that contain electrical issues. As simple as connecting a battery maintainer is, I’m always careful. Hopefully, you never see your dash look like a Christmas tree.

 

OK good to know and I will for sure NOT do that again.
So far all is good with the SDD and clone cable.
Learning more with each operation too.
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