I have a 1993 Cherokee, 4.0L auto trans. 160k+ miles.
My headlights flicker on and off randomly while I drive. I first checked all the fuses and they looked ok. Then I took off the airbox and there is no corrosion on the wiring harness. I followed that cable to a ground on the driver's side and brushed it off and tightened it down. The headlights still flicker. Usually the headlights stay on for a couple minutes then, out of the blue, they'll start cutting in and out. The flickering can last for a few seconds or a few minutes. I cannot tie the flickering to any specific event such as hitting a bump or turn signal usage. I tried to artificially re-create the flickering by jiggling the wire harness, ground and other headlight cables with no success. The only thing I can do is drive around the block at night for about 10 minutes until the flickering starts to happen but this hasn't helped me diagnose the problem.
Also, it's only the two headlights that flicker. The parking lights, tail lights and turn signals all work fine.
Any help would be greatly appreciated.

 

I think that I might have/had the same problem. I replaced the switch to the headlights (relatively inexpensive) and it seemed to fix the problem...Once I replaced the switch and put everything back together...My windshield wipers wouldn't work(and I still had the flicker)...turned out that I connected them wrong...and I haven't had the problem since...I got the replacement part from Advanced Auto Parts between $31 and $71...Good luck. Let me know if it fixes your problem.

 

i was gonna say bad headlight switch also......

 

my lights started to do that too, turned out a ground wire on the engine had broke

 

I bought a new MasterPro Headlight switch for $16 and installed it yesterday. It didn't fix the problem.

Switching it out was a big pain in the rear, though. The manual on the shelf at the auto parts store made it appear to be easy in just a few steps, but it wasn't. I started by disconnecting the battery. pulled the light switch to the on position and reached up under the dash, pushed the little spring release button and pulled the **** out. Unscrewed the nut that was behind the **** and expected the whole assembly would magically fall out from behind the dash. But it didn't. The manual didn't explain how to actually get the assembly out from behind the dash, it only stated to disconnect the old one, connect the new one and replace everything in the reverse order in which you took it apart.
After about fifteen minutes of twisting my arm up under the dash and through the rat's nest of electrical cables with no success of pulling the old switch down, I gave up trying. I ended up taking Instrument panel off and managed to switch it out by going over the top of the steering column through the instrument panel.
So tonight I decided to drive around and after about ten minutes of operation, the headlights started flickering again. I have no clue what could be the problem now.

 

check your grounds and check the steering column wiring (high low beam switch is there) My old column was busted up and I had a similar problem,now I replaced the whole column but you might just have some wires that are loose. Also check your high low beam switch on the column see if that flickers them and you might have found your problem. adn first and foremost check your battery to make sure your connections aare tight and good. (you never know sometimes the easiest check is the answer.

 

So we finally have a nice February day here in Chicago: sunny, with a high of 38. So I took the Cherokee over to my buddy's driveway and took apart the whole headlight.
On the driver's side parking light I found a red wire spliced to a blue wire. The red wire running down behind the front bumper and in to where there used to be a fog light. I think they were after-market anyway.
Back story: a few weeks ago I came out to find the driver's side fog light was missing. Whether it had fallen off, knocked off, or ripped off, I never knew. But the fog lights never worked to begin with, so I didn't really miss it.
Anyway, I noticed there was about half an inch of black wire hanging from the bottom of the bumper next to where the fog light used to be. 'Aha!' I thought, as I could only fathom that this could possibly be the bad ground that's giving me these problems. So I unwrapped the electrical tape from the blinker wire, removed the red wire, removed the fog light from the passenger side, which surprisingly wasn't wired in to anything (anything that I've found, yet). I put the headlights back together, re-connected the battery, started the truck, turned on the headlights and waited. Sure enough, about ten minutes into running, the headlights started blinking again.

Still haven't fixed the problem.

A guy at the bar seems to think the problem is with the headlight switch overheating, which he claims would be caused by corrosion or fraying on the wires, in turn causing the lights to pull too many amps. He suggests I change out both headlights, since I already replaced the switch.
I also have another buddy bringing me a wire cap in a bit to better fix the frayed wire from the parking light. I'll keep you all updated.







this is video of what the headlights are doing: (FYI: Clicking this pic will take you to the video at photobucket)

 

I have the same problem but mine seems to be caused by bumbs or excelleration I will be changing the homemade electrical the previous owner did for the fog lights first then I am checking the ground wire hopefully I won't have to replace the switch.

 

This is where the red wire running to the fog light was spliced. I threw a wire cap on here and I still have the headlight problem.


I found this connection, corroded as heck. I don't know what it is. It's behind the battery, in front of the fuse box.

 

You also may want to look for any small boxes under the dash - that almost acts like a wig wag malfunctioning...wig wags are the switches in headlights that make them flash to brights on emergency vehicles. If this vehicle was ever in service as a K9 unit, forest service unit or anything, it may have had wig wags. Just throwing the idea out there.

 

I bought two new headlights, new fuses and this battery cable cleaner stuff that's supposed to clean out corrosion. I sprayed this stuff on that corroded wire thingie above and half the plastic casing broke apart in my hand. On the plus side, all the wires inside it are now corrosion free, so i wrapped it up with electrical tape. I don't know what the part is so I don't know what the replacement would be. I sprayed the cleaner into the headlight terminals, battery terminals, grounds, basically everywhere there was a wire. Put the two new headlights in, swapped out new fuses and put everything back together. I drove around for half an hour without the flickering problem. I don't know if any of that actually solved the problem, or just made it less likely to occur again.

 

FUDGE!!! the problem came back, about two weeks ago I noticed the flickering had come back. I've been racking my brain for two weekends trying to track this problem down. It's gotten to the point where i can't go two minutes without the headlights cutting out on me. So I'm gonna take it to a mechanic in the morning.

 

It would be very helpful to find out what your mechanic says...this is starting to get dangerous/annoying. thanks. I've replaced everything but the wiring harness. I noticed that if I sit at a particularly long light or in the drive thru...that it will flicker also...So I'm thinking the guy at the bar may be on to something...but where to start? also, I don't know if I mentioned this earlier..but when I switch my lights to high beams...my gauge lights turn off. switch back to low beam and they come on...

 

mine had the random flickering issue, until the headlights just wouldn't come on! parking lights were okay, just headlights were out.

i too thought it was the switch, even checked with dealer - what a ***** to get out the first time!?!?! - took me 30 min to find the little button on the switch to release it!?!?! - so, i replaced it with two different new ones with no luck! returned the switches for refund.

pulled a wiring schematic and figured out that the high beam lever connector is where everything happens - so i bypassed the bad 'connector' on the lever and got everything to work - except, now for the high beams to stay on, i had to hold the lever back, it wouldn't stay in high beam and the lows were on too! - good enough for me, no more random flickering and i very seldom use the high beams.

however, come inspection...they wouldn't pass me because the high beams wouldn't stay on! wtf!?!? ordered an new lever ~$60, replaced it, passed inspection - now worries. all's been working since.

 

i've been having the same flickering problem as well. My jeep has stock fog lights that do not work at all, and then there were after market fog lights added on by whomever had it before me. Instead of the person hooking them up properly to a switch inside the cab, he wired them directly into the parking lights so that when the parking lights are on, the fog lights would be on. So I disconnected them and rewired the fog lights to a switch and fuse inside the cab. Long story short, didn't fix the problem. Along with the flickering head light, I've always had the problem of when I shift to reverse, the back-up lights dont turn on right away, they seem to delay a few seconds and in some cases, they do not come on at all. It seems as if the Jeep does what it wants. Also when I activate my left turn signal, I get the proper left turn blinkers in the front, but the back I get four way flashers.. confused as hell..