I recently replaced the headlight assembly with a used unit off eBay. The low beam (xenon/HID) turns off by itself after an hour or so. Occasionally, turning it off and back on will reset the issue temporarily. I tried swapping the bulbs but the problem persists. I checked to make sure that all connectors were in installed correctly.

Does this point to an issue with the ballast?

It's a pretty good chance it is the ballast. You can swap sides to be sure.

It could also be a headlight relay going bad. Those are really easy to swap. More likely it is the ballast I think, but never hurts to check the relays.

Oh, and check and make sure your charging voltage is good. I had some headlight issues when my alternator got flaky.

Thanks Rockwood. It looks like I have 2 different types of ballast between the headlights. So I do not believe swapping ballasts is going to be possible?

Charging voltage is steady at 13.8V. Rest of the lights are all fine. How do I check the functionality of a relay?

So each ballast is different?

Correct. The driver's side is similar to this with just the one connector:https://www.ebay.com/itm/OEM-Infiniti-Q ... 5d&vxp=mtr

The one on the passenger side (and the one on my original headlight which is cracked) are like this with 2 connectors: https://www.ebay.com/itm/OEM-Infiniti-Q ... sL&vxp=mtr

All the other connectors that plug into the vehicle's harness are same though. So, I'm a little lost here.

For relays, swap the two relays between sockets - left to right, right to left. Test and see if the problem moves to the other headlight.

For ballasts, the 2001's and most 2002's had ballasts with two plugs. There is an igniter in the headlight harness in this configuration.

In late 2002 or so, they changed to a one plug ballast with the igniter built into the ballast. Headlight harnesses are different. So I think you ordered a newer style headlight?

Since you are working on it, you might check your grounds - there is a black wire on the back of the plug socket - make sure the connector is tight. There are some grounding bolts up at the top of the inner fenderwell on both sides.

If swapping relays does not help, you are kind of left with a ballast problem I think.

Swapped the relays around. Same issue.
Interestingly, the headlight was functioning fine for an hour. I pulled in at a rest stop and turned the car off and restarted it. The headlight flickered for fraction of a second during the start up/cranking and went out when the engine caught/started running. Turning the car off + turning off the lights along with restarting the car and turning the headlights back on allowed the headlight bulb to come on again.

Does this point to a wiring issue?

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.

What was the reason you replaced the headlight? Was it doing the same thing?

Interesting. Your post was very insightful on how the HID headlights work.

The reason I replaced my original headlight assembly was because it’s been cracked since the time I bought it. And I ran out of patience with having to duck tape the thing every week to prevent moisture/dampness from getting in.

Is there any way to test just the ballast?

brickbox wrote: ↑

Wed Oct 03, 2018 7:44 pm

Is there any way to test just the ballast?

can you swap the ballasts

I don't know of a way to test the ballasts. Stay away from the headlight circuits when lit - there is enough voltage / current there to get you in trouble. You probably know that, but I thought I would mention it to be sure!

Still a bit of a guess, but the problem appeared after you swapped headlights, which says ballast or wiring harness to the bulb. Those are new parts if I understand correctly (and you checked bulbs already).

If you still have your old headlight, swap the old ballast and headlight wiring harness back in. That should cure the problem.

hahaha yeah, every time I work on the headlights, I disconnect the battery. Not particularly thrilled about being zapped with 12,000V
I still have my old headlight. Are the ballasts swappable between the 2 connector and single connector versions?

Also, I gotta go back and see how much corrosion those tiny bolts holding the ballasts have...

Yep, you can use the older ballast - it will work fine. You will of course need to use the two plug wiring harness that works with it. The igniter is in that wiring harness in the older version.

You must be pretty close to having your Q all fixed up - any other big projects?

Perfect, that's what I was hoping to hear. It might be next week before I get to it.
This weekend I'm going to be busy getting my project car up and running (old school RWD Volvo )

The Q is all fixed. No real big projects remain. I need to drain and flush the PS fluid. Outside of that, she's running like a swiss watch. Even gave her a name.

Creeping up on 172K miles, knock on wood, she's been very reliable so far.

Next real big $ item for me is going to be a second set of rims (which seem really hard to find for cheap) and winter tires.

I had an issue with one headlight turning off, after a while I realized it was turning off after using my turn signal specifically when the switch clicks back to the normal position. The only temporary solution was the turn the key off and back on.

I installed a new "multi-function switch" turn signal and all is well now.

I tried messing with the combination/multi function switch and it didn't seem to do anything.
Oddly enough, over my past couple of commutes, the headlight has not turned off. Still kinda in limbo about what's going on outside of just changing out the ballasts.

This problem is back with a vengeance!!
For those are catching up, I replaced my drivers side headlight assembly because the lens was cracked when I bought the car. This headlight assembly had the newer style single connector ballast.

The replacement unit came out of a 2001 and has the two connector ballast style.

I was able to pull the single connector ballast and the wire harness off the “old” headlight assembly that is original to the car.

However, I’m stuck on how to remove the 2 orange wires that are inside the replacement headlight assembly? Pics 3 and 4 in attached album.

The reason for this switch being that the 2 connector ballast is dying and I need to constantly cycle it on/off to get it to run.

I’m at my wits end because the Q is torn and I need her for my commute!!

http://imgur.com/a/hdi9y65

It looks like the orange wires are connected to the back of the silver box. But how do I loosen the silver box? I can't see any fasteners when I take a peek around the headlight assembly. Has anyone swapped these out before on their QX4?



This is how it looks inside the headlight assembly (the one with 2 connectors for the ballast):



The newer design that was replaced due the cracked lens has a much simpler design where the connector can be easily accessed:

Anyone at all? I’m stuck here and can’t really figure out how to swap the orange wire out!