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Discussion Starter #1
Hi all,
First off, want to say thanks in advance if anyone can help me diagnose this little but frustrating problem.

Here's the deal. Just bought a new 2013 Wrangler JK sport. I've had zero issues with this vehicle but what seems to be an electrical issue. For starters, I've searched this forum and others for similar issues but came up empty. I've also brought it to the dealer where they stated "no codes come up so it can't be major"...

Here's the problem. When the Jeep is on (idling or driving) the instrument cluster lights flicker, the radio display flickers. The interior dome lights also flicker. On the exterior, the headlights, fogs, etc. also flicker.

The flicker is constant - meaning the lights flicker at the same rate/speed at which the engine is running, so its almost like a quick pulsating. It's incredibly noticeable at night (and annoying driving on a dark road with your headlights flickering) and a bit tough to see during the day (obviously).

To me, it seems like a bad electrical ground but not sure what would impact the entire lighting system. Battery terminals look fine - I mean, it is brand new. Any thoughts/ideas on what could be causing this harmless but annoying flicker?

Thanks again,
Tim
 

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I'm far from knowledgeable on this subject. But, I have picked up from reading on the Jeep lighting system that the Power Control Module (PCM) modulates the power fed through the CANBUS to all the lights and the electrical system so that the voltage varies from about 4 to about 13 volts (IIRC) very quickly.

Either you are very very perceptive and are seeing what most would not notice - a high frequency flicker - or something is wrong and maybe the power is pulsing too slowly.

I'd get on the dealer at least to put your concerns and their diagnosis in writing just so you are covered on this for the future.

Believe me, if I'm way off base on my understanding here, others will be glad to give you the correct explanation....
 

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Discussion Starter #3
Up Hill,

I thought maybe I was being ultra sensitive, too, but my wife notices it as well. I just wish the service dept. would use their brains and actually troubleshoot rather than rely solely on codes and computers.
 

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Up Hill,

I thought maybe I was being ultra sensitive, too, but my wife notices it as well. I just wish the service dept. would use their brains and actually troubleshoot rather than rely solely on codes and computers.
Try getting them to compare your Jeep with others on the lot. Sometimes they will admit to noticing something is different when it's put right in front of them.

I'm lucky to have a pretty good relationship with my dealers servicewriter and I get pretty good service, but I know how frustrating it can be when they just refuse to see the obvious....
 

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To me, it seems like a bad electrical ground but not sure what would impact the entire lighting system. Battery terminals look fine - I mean, it is brand new. Any thoughts/ideas on what could be causing this harmless but annoying flicker?

Thanks again,
Tim
This is not something I have noticed in mine, but i feel like I would as part of my job deals with graphic design and I notice when displays / monitors have bad quality / flickering.

I would imagine the problem is actually a capacitor issue somewhere - as a capacitor's job it to "smooth" out electricity - this is important when you have a power source with a low frequency. LED's can flicker really bad when you replace standard tungsten bulbs in cars with LED replacements. LED's are very susceptible to flickering because of their instant on-off (and tungsten have a glowing effect that minimizes this)... So Capacitors are required to smooth out the power to prevent flickering.

I'm not sure what lights the dash lights in our vehicles, but I'd suspect a capacitor issue somewhere.
 

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Discussion Starter #6
I'm trying to get video of it to show to the dealer. However, it's such a low frequency flicker that the camera won't record it. Maybe I'll have service dept. drive it home one night? This may sound dumb but where is the capacitor located?
 

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I'm trying to get video of it to show to the dealer. However, it's such a low frequency flicker that the camera won't record it. Maybe I'll have service dept. drive it home one night? This may sound dumb but where is the capacitor located?
Could be some tiny part in a circuit board somewhere the size of 1/2 a AAA battery... I really have no idea how car electrical systems are wired for the most part.... I'm basing this on some electrical knowledge I have of home-made windmill style generators and LED bulbs.

You'd may be able to capture it if you have something that can record at 60 frames per second - Most people can only distinguish a rate of 40 frames per second, which would suggest that your flickering is slower than that, so it could be fast enough, but maybe not.
 

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Discussion Starter #8
Is it possible its a bad battery cell? Does anyone know if the Jeep battery's are able to be opened to test each individual cell? I recall someone having electrical issues and found that one cell was dead.

Also, does anyone recall how to create a temporary ground to see if its a bad ground? I recall you connect a jumper cable to the negative terminal then the other end of the cable to metal somewhere on the truck, no?
 

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....Also, does anyone recall how to create a temporary ground to see if its a bad ground? I recall you connect a jumper cable to the negative terminal then the other end of the cable to metal somewhere on the truck, no?
It's not that simple. The battery-to-chassis ground strap is just the last leg of the ground circuit. Every electrical circuit in the Jeep is grounded to the chassis somewhere to complete the circuit back to the negative side of the battery.

If your problem is a bad ground, it could be in any of a number of places!
 

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Flickering lights is usually due to a loose connection somewhere in the power supply circuit. However, a loose connection usually is random and flickering occurs when the connection gets jostled or moved. You claim the flickering is consistent with engine RPM. That should rule out a loose connection unless the engine is causing the vibration which makes and breaks the connection. If it only happens when the engine is running it probably is related to the charging and or supply circuit.

You might try to see if you can recreate the flicker with the engine off by shaking your Jeep and the various wires leading to the lights. If you can re-create it with the engine off then it shouldn't be to hard to locate the loose connection. Just because you can't though doesn't mean it isn't a loose connection, just that you can't recreate it without using your engine.

Does everything flicker, headlights, taillights? If some stuff does and some doesn't then trace the wiring back to where the supply between stuff that flickers and stuff that doesn't join together. Everything joins at the battery and ground so you can work forward from there.

If you have a 12v spotlight you can use that to trace wiring to see where the flickering starts. Start at the battery and follow the positive wiring leading to the flickering lights until you find out where it starts. Then trace the negative path if you have too.
 

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Same issue

Hey Up Hill

Any update to your issue? I have the SAME EXACT issue with my 2013 JK Sport. I'm about to go to the dealer and go all crazy on them. Its only 2 months old....
 

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Have you checked the alternator voltage at idle? It might be a bad alternator. The exterior lights are pulse-width modulated, but I don't think the instrument cluster is.
 

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Have you checked the alternator voltage at idle? It might be a bad alternator. The exterior lights are pulse-width modulated, but I don't think the instrument cluster is.
I was thinking this too. I had an alternator go in my old car and all the lights would flicker at idle it did it for a few weeks before the battery went dead and then it wouldn't start. Get the dealer to test your battery and charging system. It could be the regulator in the alternator not performing.
 

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I had this same problem with a 2003 vw gti, they ended up replacing the battery and alternator, never happened again.
 

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Discussion Starter #15
Quick update. Brought this issue to the attention of another dealer - had them test the battery, said the battery was strong. Once again, because they could not get the vehicle to reproduce the problem (because the garage was too bright) he told me to bring it in another time...so frustrating...

Another new symptom: Yesterday I was stuck in the snow and every time I stepped on the accelerator the light flickered badly as the tires spun..very prominent dimming as I step on and off the peddle...Alternator??? Is there a way I can check the alternator to see if its bad? I'm at a loss now...thanks
 

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That is the traction control that makes the lights flicker when you were stuck. Did you notice on the dash the traction light flashing when the wheels were spinning?
 

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I know this probably isn't helpful... but my 2012 JKUR did this same thing.

There were times where the flickering was very noticeable... and it was most noticeable on the back of other vehicles (from my headlights) or on my garage wall - but I could see it happening everywhere (gauges, radio) when it did. The dealer I bought it from told me that I was basically crazy and that there was no flickering occurring.

The dealers around me wouldn't do anything because they said they couldn't recreate the problem. One of the service guys at a dealer in New Braunfels, TX met me at my Jeep when I was pissed off and just about to leave after picking it up and told me, "hey - I just want to let you know that I did notice the flickering late last night against the side of our building when we were testing... but it's not throwing any error codes or causing any safety issues, so Chyrsler's STAR team is unwilling to say that it's a problem. The reason is once they acknowledge it's a problem, they have three tries to fix it... but they have no idea what is causing this. They are considering this 'flicker' within factory specifications for now. Sorry we can't do more."

I ended up having the Pentastar engine ticking along with some bad manual transmission problems on this Jeep too within the first year. I fought with Jeep for about 8 months and they finally replaced it with a new 2013 JKUR - which didn't have any of the same problems my 2012 had, including the flickering.

I now have a 2014 JKUR and it's flicker-free as well. Not saying our flickering issues were identical, but the issues I ran into were *not* normal. I've owned an '08, '11, '12, '13, and now '14 JKU and only the '12 had the flickering problem. The '08 and '11 had their own issues that resulted in 'rage quit' trade-ins. My 2013 was issue free, and my 2014's only issue so far is that the LEDs in the cup holders don't work.

From my ridiculous (and insane, according to my wife) history with owning JKs, I'd have to say Jeep's QC process is total shit... but I'm determined to find one I can hang on to forever that doesn't have any major issues. I think this 2014 might be the one. *fingers crossed*
 
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