Hi, first off let me say this forum rocks. I am a new member, but have been using the site for a couple of years now while working on my step daughter's '01 QX4. It's a wealth of information posted by some very helpful folks.

The headlights on our QX4 started flickering and shutting off recently. Very frightening deal for a young lady driving home from college in the dark. After many hours of reading and then replacing the switch/stalk, the same problem continued to persist. As a last resort, I started an account on here just before Thanksgiving (same user name) and created a long detailed description of the problem, symptoms, and what I had done so far. I received a great thorough response from another member on testing and troubleshooting the relays, but when I had time to actually try it, I was unable to access the nicoclub site to read the posts. Like the page wouldn't load at all. Same problem whether trying from my phone or pc. So I presumed the server was down for maintenance or something.

A couple days later, I realized the site was working again, so I tried to go to my bookmarked thread to read the other gentleman's response about the relays, but the link didn't work. So I tried to login and find it from my account, but got a bad username error instead.

So looooooong story short, it appears my account and thread were deleted for some reason, and now I have lost all of the info posted by both myself and anyone else who responded. I was able to recreate a new account with the same username and info, but obviously that doesn't help with the lost thread. Does anyone know what happened, if it's possible to resurrect this thread, or how to bring this post to the attention of an admin?

There was a hack around Thanksgiving and pretty much all the posts between Nov 19 and Dec 1 were unrecoverable. See this post:

november-service-interruption-please-read-t630160.html

If I recall your original post correctly, there are a couple things you could check. The headlamps have separate left/right relays with separate fuses, so it's fairly unlikely that anything there would cause both headlamps to malfunction. They also use different grounds, and the only common circuit elements are the fusebox main supply, the headlight control unit and the wire going from it to the relays, and the combination switch. You already replaced the latter and the ballasts, so check the Purple/White wire at either one of the headlight relays while the headlights are misbehaving. You should see 0V or very close to zero. If not, there's either a problem in the PPL/WHT wire or a malfunction in the Headlight Controller (underneath the left kick panel). If you do see 0V then check the fat RED/YEL wire from the relay, if that's hot then your problem is in the headlights or the ground wiring. You can run a voltage-drop test on the grounds to verify those. One last thing, you didn't mention if you replaced the Ignitors (the steel-clad wires connecting the ballasts to the bulbs). Those aren't simply wires and they can fail.

VStar650CL wrote: ↑

Mon Dec 06, 2021 8:41 am

There was a hack around Thanksgiving and pretty much all the posts between Nov 19 and Dec 1 were unrecoverable. See this post:

november-service-interruption-please-read-t630160.html

Ah, that explains it completely. Thanks VStar.

VStar650CL wrote: ↑

Mon Dec 06, 2021 9:10 am

If I recall your original post correctly, there are a couple things you could check. The headlamps have separate left/right relays with separate fuses, so it's fairly unlikely that anything there would cause both headlamps to malfunction. They also use different grounds, and the only common circuit elements are the fusebox main supply, the headlight control unit and the wire going from it to the relays, and the combination switch. You already replaced the latter and the ballasts, so check the Purple/White wire at either one of the headlight relays while the headlights are misbehaving. You should see 0V or very close to zero. If not, there's either a problem in the PPL/WHT wire or a malfunction in the Headlight Controller (underneath the left kick panel). If you do see 0V then check the fat RED/YEL wire from the relay, if that's hot then your problem is in the headlights or the ground wiring. You can run a voltage-drop test on the grounds to verify those. One last thing, you didn't mention if you replaced the Ignitors (the steel-clad wires connecting the ballasts to the bulbs). Those aren't simply wires and they can fail.

Yes, you have a fantastic memory. Thank you for the thorough response; I took a screenshot this time so I can't lose it. I did not realize there was a headlight control unit underneath the kick panel. I am not at all familiar with HID lighting, but am learning as I go here. I guess I need to seek out a wiring diagram and try to comprehend the logic of the circuits (in addition to doing as you suggested). I was under the impression the stalk/switch sent juice to the relays which in turn delivers power to the ballasts, which step the voltage way up for the bulbs.

So in that chain of components, where does the controller fit in? Is it in between the switch and the relays? And what do the igniters do? I did not replace them when I was swapping ballasts because I wasn't even aware of them.

Since it may be one light or the other, or both that quit, it makes me believe whatever turns the relays on is faulty, assuming the wiring is not damaged somewhere along the way. I went ahead and picked up a new pair of relays just to eliminate dirty relay contacts from the equation, but I don't expect that to resolve the issue. I will do as you suggested above one night this week as well. Thank you for your input.

The Controller reads the switches and then turns the relays on as commanded. It's mostly there to give you auto lights and auto shutoff when the lights are left on (a dinosaurian leftover from the pre-BCM era). The tests I outlined should give you a good idea of whether the problem is in the Controller or the lights themselves.

As for my "fantastic" memory, that's actually the first thing that goes with old age. And the second thing is... umm... umm... patience, it will come to me...

VStar650CL wrote: ↑

Mon Dec 06, 2021 2:52 pm

The Controller reads the switches and then turns the relays on as commanded. It's mostly there to give you auto lights and auto shutoff when the lights are left on (a dinosaurian leftover from the pre-BCM era). The tests I outlined should give you a good idea of whether the problem is in the Controller or the lights themselves.

As for my "fantastic" memory, that's actually the first thing that goes with old age. And the second thing is... umm... umm... patience, it will come to me...

That's ok, there's plenty of stuff I'd rather just forget about anyway. The purpose of the controller makes sense now. I hadn't considered what managed the auto functions. I'll test as you suggested and report back.

Thanks for your patience - Sorry about the interruption.

In 17 years, this is the first time we've lost ANY content, so suffice it to say we're taking this one REAL seriously.

Ok Vstar, I replaced both relays this evening and took a test ride. The right light went out just a couple miles down the road. I pulled over to test the purple/white wire to that relay for voltage, but am not able to probe the end of the wire without remove the relay. So I pulled the relay out and tested that terminal, and it showed 36mv. Upon reinserting the relay, the light came back on.

Just down the road, the same light went off again. This time I left the relay installed and pierced the wire with my probe, and it shower 36mv again. Pulling the relay and plugging it back in, once again made the light come back on.

As I was testing that relay the second time, the other headlight also flickered and went out. It also shows about 36mv on the purple/white wire when probed while off.

So then I looked at the other wires to those relays. The fattest one in there is red/green stripe, and the red with yellow stripe is thinner, so I wasn't sure which one I was supposed to check for power. I need to get a wiring diagram and study it I think.

Does any of this help narrow down the problem? It all seems very random and strange. I'm wondering if the controller you mentioned in the kick panel is failing. I don't know where to get one or even what they're called yet though. Need to research that I reckon.

Thanks!

The 36mV on PPL/WHT is essentially ground, so your controller is working. The fat RED/YEL on each relay is the output to the headlight, if those are hot then the relays are working and your issue is in the headlights or headlight grounds. Frankly this sounds like your high-voltage supplies are cutting out, so back to the original question, did you change the Ignitors along with the Ballasts? If not, that's probably your issue. If so, check your power and ground at the Ballast connectors.

VStar650CL wrote: ↑

Wed Dec 08, 2021 5:16 am

The 36mV on PPL/WHT is essentially ground, so your controller is working. The fat RED/YEL on each relay is the output to the headlight, if those are hot then the relays are working and your issue is in the headlights or headlight grounds. Frankly this sounds like your high-voltage supplies are cutting out, so back to the original question, did you change the Ignitors along with the Ballasts? If not, that's probably your issue. If so, check your power and ground at the Ballast connectors.

I think we are making progress here! So I need to probe both of the red/yellow wires (I sure hate piercing the insulation, but don't see another way) and verify power while the lights are acting up; I suspect they will be hot as intended.

And I did not replace the igniters when I swapped the passenger ballast, because I didn't realize they existed at that time. So there is a very good possibility they are worn out. Obviously, I know what "igniter" means, but in lighting terms, what exactly do these things do? It seems like the problem gets worse after the lights have been on a few minutes. As if something may be failing once warmed up.

I meant to look for/identify the igniters on the vehicle last night, but it was dark and cold and I forgot all about them. I can't seem to find them on the headlight diagram on the Infiniti dealer parts sites, and googling it just brings up an $800 ballast. I see a few pics of used originals on google, but don't really come up with any reliable sites I recognize to purchase replacements. Don't see anything QX4 specific on Ebay either. Chances are, 20 year old used replacements would be as bad as what I've already got anyway. Is there a work around, or a trustworthy aftermarket alternative available if it turns out to be the igniters?



Edit: here's a quote from another guy's thread, who was having similar issues. This explanation makes a lot of sense.

"I have had a bad ballast, and I had to cycle the light switch to get the headlight to come back on, like you are doing. That cycles the igniter and relights the bulb until the ballast voltage drops too far again and the light goes out. If I remember correctly ballasts are supposed to output 12,000 to 15,000 volts to keep the bulb lit. The bulb will not relight until you hit it with the igniter which momentarily puts out 20,000 volts or so."

HID systems are basically high-voltage arc welders inside a bulb, and the ignitors basically contain a capacitive jumpstarter for the arc. I never replace ballasts alone, I always get them with ignitors because the ignitor is the problem at least half of the time. Bad news is, ignitors are hard to find separately. Good news is, you don't need to use Nissan ballasts or ignitors. Matsushita and it's China subcontractors make probably 99% of the world's ballasts, so the cheaper ones on eBay and Amazon are generally fine as long as they have a Matsushita part number. Grab that off your ballasts and then use it to find compatible ballast-with-ignitor combos on the net. The Matsushita number for Nissan ignitors will usually start with EANC for the small-housing types or LENA for the large housings. Pretty much anything with the right series numbers and connector cavities will work.

VStar650CL wrote: ↑

Wed Dec 08, 2021 8:49 am

HID systems are basically high-voltage arc welders inside a bulb, and the ignitors basically contain a capacitive jumpstarter for the arc. I never replace ballasts alone, I always get them with ignitors because the ignitor is the problem at least half of the time. Bad news is, ignitors are hard to find separately. Good news is, you don't need to use Nissan ballasts or ignitors. Matsushita and it's China subcontractors make probably 99% of the world's ballasts, so the cheaper ones on eBay and Amazon are generally fine as long as they have a Matsushita part number. Grab that off your ballasts and then use it to find compatible ballast-with-ignitor combos on the net. The Matsushita number for Nissan ignitors will usually start with EANC for the small-housing types or LENA for the large housings. Pretty much anything with the right series numbers and connector cavities will work.

To be clear, are you referring to new, current production Matsushita ballasts/igniters? Do you have a link to an example? I think I have to take the front end apart and remove the headlights again to get the part numbers off the ballasts, and the passenger OEM replacement was labeled in Japanese, so I'm hoping it shows an English number. I know the passenger side is the smaller style ballast with the single plug on it, but not sure if the other side is the same yet.

Ok cool, thank you. I looked at several of those and wondered if they would be suitable replacements. Would I need to cut the plug off and hardwire it into the harness, or is something like that intended to plug and play? Sorry if that's a stupid question, I'm at work and haven't been able to research much yet.

If you look at the back side pic, the ignitors are removable. There's a standard latching connector shell with a 1-screw metal bracket holding the wire to the body of the ballast. So you can transfer just the ignitor if you want, or replace the whole thing as an assembly. The jumper cable they show on the power side is for cars that use "H" type connectors in the car harness, but that will just unplug too. Your harness should plug straight into the gray shell on the body of the ballast.

That's exactly the explanation I wanted to hear. Would that bulb socket fit the oem housing for my '01? I presume so, but since it appears to be a direct replacement for newer models, I just wanna be sure. I will end up taking the vehicle back apart before ordering anything to check part numbers, etc. regardless.

Thank you so much for your help and patience. I still need to check the red/yellow wires of course, but this sounds like a very feasible solution.

Edit: I was just looking at pics of the oem ballast and igniter, and it appears to use a 5 pin plug at the ballast. I believe the pic below is identical to the one I replaced on the pass side. Unless I am misunderstanding, it looks like it would require at least a little bit of splicing. Which is fine, I work on LS swap harness and stuff, so I can handle it. Just trying to understand what I'm in for.

Yep, that's definitely an oldie. I'm not even sure that's OE, the WD's just show power wires in and low-beam wires out, with separate high-beam connections. That looks like a combo setup for a bulb with a high/low aiming solenoid.

VStar650CL wrote: ↑

Wed Dec 08, 2021 10:41 am

Yep, that's definitely an oldie. I'm not even sure that's OE, the WD's just show power wires in and low-beam wires out, with separate high-beam connections. That looks like a combo setup for a bulb with a high/low aiming solenoid.

It's identical to the original OEM ballast I removed, except for the Japanese writing on the label. It appears there were two versions used in the early 2000s, a rectangular ballast with two plugs and the one in that picture, which is the one mine uses. So now I'm back to confused again.

Could you elaborate on the "combo setup for bulb with high/low/ aiming solenoid"? I ask because the passenger light is aimed way low, but there doesn't appear to be a way to adjust it. There was a clicking coming from that headlight housing when we first got the vehicle, and it appears there is a motor or something inside that is stuck that is supposed to aim the light automatically. I believe I pulled the plug off of it when I replaced the ballast on that side.

That's what I was wondering. The WD's show a separate high-beam bulb, which is what most HID setups use. That's because HID's take a few seconds to illuminate, which precludes "flashing" if the lights aren't already lit. However, there are also setups that use a small solenoid or motor to raise the focus of the bulb to get high and low from the same bulb. There are also "auto aim" setups that detect rear loading and/or pitch of the vehicle and raise or lower the headlights accordingly. Your "clicking" could come from either one, but that setup looks suspiciously like a single-bulb high-low. I'll have to look around and see whether Infiniti used any setups like that on the QX4, maybe the diagrams in Identifix are wrong.

Hmm, nope. ASIST shows the same as Identifix, but it shows your clicking is coming from a leveling motor, not a high-low. That's a pretty bizarre ballast setup for a single-focus lamp, but it must be an "assembly" which is why it isn't showing up in the WD's.

Ok, that makes sense now. This QX4 has separate traditional high beam bulbs in addition to the HID low beams. And they appear to have the leveling motor setup you mentioned. I have noticed the 1/2/3/4 dial on the dash, which I think I read is supposed to adjust them up and down a little too. Of course, that doesn't work when the motor is stuck and/or unplugged. I don't know if those motors are serviceable or replaceable, but I would like to get the aim fixed too once I get them to stop flickering and going off. I couldn't figure out how to remove the motor without breaking it last time I had it all apart.

What is ASIST? I'll have to google Identifix too, I am not familiar with these resources. I guess I need to find a wiring diagram so I can see where each of the 5 wires on that ballast plug go, and which ones would need to be spliced into a new ballast.

ASIST is Nissan's service documentation database, Identifix is a professional database similar to Mitchell or Alldata (but better in my estimation). ASIST is proprietary and Identifix is subscription, neither one is net-accessible for the general public.

Gotcha, I thought that may be the case. I'll do a little more scrounging the googles and forums for a diagram when I have more time.

There are actually two SM's depending on your VIN. They have the earlier version here in Nico, for VIN's up to 200000 for 2WD and 200100 for 4WD. Here's a link, the headlight WD's start on EL-29:

https://www.nicoclub.com/service-manual ... 0%2FEL.pdf

For VIN's 200001+ or 200101+, here are the WD's only, I can't grab the whole section:

I forgot all about the manuals section on here! Thank you, this should be very helpful. Our QX4 is the newer series and AWD.

VStar650CL wrote: ↑

Wed Dec 08, 2021 4:31 pm

There are actually two SM's depending on your VIN. They have the earlier version here in Nico, for VIN's up to 200000 for 2WD and 200100 for 4WD. Here's a link, the headlight WD's start on EL-29:

https://www.nicoclub.com/service-manual ... 0%2FEL.pdf

For VIN's 200001+ or 200101+, here are the WD's only, I can't grab the whole section:


EL-490.jpg
EL-491.jpg
EL-492.jpg

VStar, I wanted to take a minute to thank you again for all of your help. I FINALLY got around to working on the lights again this weekend (busy college kid schedule, snow, etc.) and they appear to be good to go.

I ended up installing a pair of the cheap Amazon ballasts/igniters. I should have taken pics of the process but didn't think about it until afterward. I found that two of the 3 lugs on the new ballasts even aligned with the threaded studs that attached the original ballasts to the headlight housings. So I just cut off the third one, and bolted the new ballasts right on in place of the originals.

I cut the plug off of the input side of the new ballast and spliced it into the factory headlight harness where it attaches to the vehicle. The new socket fit the original Infiniti bulb, so I didn't have to do anything to the output side, except route it thru the grommet into the housing, and dispose of the old if igniter and socket wiring.

I took a 15 minute test ride last night and they worked without a single hiccup or flicker. We are soooo happy!

Thanks again!

You're most welcome, glad you got it straightened away. Happy motoring!