Elctrical flicker...

dog_party · **Posted:** Tue Nov 13, 2007 11:49 am

I have noticed for a while that when I pull up behind someone, after the truck comes to a complete stop, the headlights dim. If I tap the fuel pedal, the lights brighten back up. Used to happen in my Jetta too, and I never had a problem so I haven't given it much thought.

...until this weekend...

We were coming back from DC and I noticed that after I changed lanes, when I turned off the turn signal, the headlights would flicker off. It happened about 1 in 3 times. Repeatable, but not absolute consistency.

The interior lights do not go off during the headlight flicker. No noticable performance change during the flicker.

Any ideas?

WoodysKJ · **Posted:** Tue Nov 13, 2007 1:35 pm

The dimming of the head lights is a typical sign of a failing or under powered alternator. When it happens what else is being used? Windo defroster, seat heaters, radio, wipers, other lights...?

All of these items have an amp draw and when they add up it can show up when the engine idles and the alt is not spinning as fast. Thats not to say either the battery or Alt is dying. just not getting enough power to power all the toys we put in the KJ's. Don't panic, just get them tested.

The flickering of the lights can also be this OR it can be that battery is dying. One of the weird things about these modern all electronic cars is that the voltage regulator is in the PCM and if the battery and/or the alt are running on their last legs, they can cause malfunctions like this.

Have the battery tested. if that does not do anything have the alt tested someplace like Auto zone or Pepboys. ad if either is bad, well there you have it. I would not go running to the stealership, yet until I knew what it was.

Good time to get a high amp alt and/or an Optima battery.

dog_party · **Posted:** Tue Nov 13, 2007 2:20 pm

Let's see...in operation at the time of flicker:
Headlamps (stock)
Foglights (stock)
Radio (stock 6-disc in-dash changer)
Heater (low setting, #1 fan setting)
It is theorectially possible that my wife's seat heater was on

The CRD was supposed to come with an Optima Red Top, but mine does not have one. The truck is going into the shop for an unrelated issue, so I'm going to have them go over it with a fine-tooth comb. It's a 31k miles, so I want everything "on the books," so it can be listed as an existing condition.

It's my guess that putting an Optima Red Top in there will fix the problem, but I wanted to get some other takes on it while waiting for my service bay appt.

WoodysKJ · **Posted:** Tue Nov 13, 2007 4:57 pm

Optima yellow tops are good too. The seat heaters do draw a few amps. Might be that your Alt is starting to show age and will need replacing soon.

Good luck.

raceinfan · **Posted:** Tue Nov 13, 2007 5:06 pm

my headlights dimfor a split second on mine also , when I hit the brakes or the electric fan kicks in etc. it's done it for quite a while now, will be replacing the battery soon

dog_party · **Posted:** Tue Nov 13, 2007 5:22 pm

If that's the case, this will be the first vehicle I've ever owned that burned a battery and/or alt in 30k miles.

Jeepjeepster · **Posted:** Tue Nov 13, 2007 5:43 pm

My headlights have always dimmed when I stop. They did that with both the stock and the optima red-top that I have now. Before I got a Capacitor for my sub they would dim alot at night if I had the headlights+fogs on.

The flicker in the head lights could be a stalk going bad. Do the fogs also flicker?

Edit: They dim if I hit the brakes too when Im sitting still.

WoodysKJ · **Posted:** Tue Nov 13, 2007 5:58 pm

a little dimming is normal, but if they seriously dim then there are other issues.

Should have asked how much. If the engine idles low and threatens to stall at the same time, might be the atl.

I thought they fixed that multi function switch long ago. Wife's 02 needed replacing, but not heard of it being bad in the 05's

bugnout · **Posted:** Tue Nov 13, 2007 6:53 pm

I've had slightly different issue, when left turn signal cancels, the brights come on for a second. I'm thinking the stalk is going bad.

SoDakJeep · **Posted:** Tue Nov 13, 2007 7:35 pm

MY O5 STALK IS FINE ONLY TIME I GET A LITTLE FLICKER IS WHEN I HAVE THE SUBS POUNDING. 2 12'S WITH A 800 WATT AMP SO IM SURE THAT ITS NORMAL. GET A YELLOW OR RED TOP THERE BOTH GREAT THAT WILL BE ONE OF THE THINGS I WILL BE DOING NEXT FOR SURE

Guest · **Posted:** Tue Nov 13, 2007 8:49 pm

dog_party wrote:

If that's the case, this will be the first vehicle I've ever owned that burned a battery and/or alt in 30k miles.

You mentioned in another post your CRD didn't come with an Optima battery. Maybe a savvy tech spotted it during a PDI and decided to gank it for his ride, and replacing your Optima with a battery that's God knows how old?

I'd blame the battery first

EDIT: Oops, I need to start reading a little harder at the OP.

myjeepwalks · **Posted:** Tue Nov 13, 2007 10:08 pm

Quote:

We were coming back from DC and I noticed that after I changed lanes, when I turned off the turn signal, the headlights would flicker off. It happened about 1 in 3 times. Repeatable, but not absolute consistency

You have a bad turn signal switch/stalk/ multifunction switch what ever you want to call it. :lol:

cmohr · **Posted:** Wed Nov 14, 2007 4:01 am

I know it sounds wacky, but, I get a flicker and even the headlights failing every now and then as well. Mostly after I've been in water and lots of dust, found that the plugs on the back of the H4 bulbs are exposed to the elements and build up a lot of crap, crap that is conductive and that shorts the system when I hit bumps or pull up, once again causing a slight bump. Cure was to get in and clean out the plugs and spray them with a water dispersant after 4x4 outings, Now not a problem anymore.

Oh, when it happened the first time I just thought it was a blown bulb, but, turned out that due to all the wet dust shorting it out the plug and wiring there had melted. So its something to keep an eye on, don't want NO Engine Bay Fires!!!

cmohr

SavageUrge · **Posted:** Wed Nov 14, 2007 7:43 pm

I have the Renegade with the factory installed 160 amp alternator. Since the day it was new I noticed a very slight dimming of the headlights when all I did was raise or lower the window. Flickering is normal. Don't worry about it. Your headlights will dim when you remove the backup power from the alternator and run them solely off the battery, this is perfectly normal. When the engine RPM's come down, the alternator isn't spinning as fast so it is producing less power, hence the dimming. I have almost 75,000 miles on my Lib, and have had NO electrical problems yet and haven't had to replace the factory battery either. This includes the addition of 55w reverse lights and a set of Piaa's on the front that I use regularly. It still starts on the first try, within a second of turning the key!

BeepBeepJeepJeep · **Posted:** Wed Nov 14, 2007 7:59 pm

I think you may be having two separate issues, one of which I have...

Sometimes when I'm turning and my turnsignal turns off, my foglights (and maybe my headlights, not sure) turn off and then on in less than a second. I think the switch for the turnsignal is going bad but it doesn't do it often enough for me to worry about it yet...

Bill

SavageUrge · **Posted:** Thu Nov 15, 2007 12:33 am

The multi-function stalks do have a rather regular failure rate. This could possibly be your issue. When you've got something with so many connections that twists two ways, pushes, pulls and moves back, forth, up and down, eventually somethings got to give.

dog_party · **Posted:** Thu Nov 15, 2007 11:49 am

I supposed it's possible that it's only the fog-lights that are flickering off. My fog-lights are always on. I'll have to try it without the fog-lights and see what happens.

If it's the stalk, it's going to be fixed under warranty. That's the big reason I'm bringing it all up now. I'm at 32k and will be well over 36k by the end of the year. So I want all the little problems listed at my stealership as "existing conditions." :wink:

Elctrical flicker...

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