Xenon headlight not working with new bulbs

[jeffmiller]

Originally Posted by 80stech

If left and right are separately controlled by the LCM then you might want to start testing there, or work your way back from the light to the ECM. A wiring diagram is going to be your best friend

I'm definitely out of my comfort zone if wiring diagrams are involved. First thing I will do is remove left headlight and try on the right side cable, see if low beam comes on. After that, I'm just going to start buying used parts on eBay and replacing them until the dang thing works again.

[Salty B.]

Try a junkyard ballast/igniter.

[crystalworks]

Proceed below:

Swap your headlight from left to right... the plugs fit both lights. That will eliminate the LCM as an issue.

You already swapped tried xenon bulbs, so no need to test those.

Then, swap the ballast from the working light to the non-working light. If it fixes... you need a ballast.

If not, swap ballasts back to original and swap the AHL/ALC (I always forget which the late models use vs. the early ones) modules under the headlights. Inspect the non-working on for corrosion while doing so. Clean with CRC electronics cleaner if any present. If no change in behavior swap the AHL/ALC modules back to original.

At this point it gets tricky because you might need INPA (or ISTA) to reset the AHL/ALC setup. I experienced your exact problem and it ended up being my AHL/ALC module on the driver's side headlight had gotten water intrusion in it. I replaced it with an ebay one of same part number (cost was very cheap ~$50). But it would still not work... UNTIL I reset the AHL/ALC in INPA.

There is a workaround... which I had to use while I was figuring all of the above out (and getting INPA/ISTA install to work) in order to drive the X5 at night. I describe that in the thread below. Basically it piggy-backs the working headlight because the LCM disables voltage to the low-beam in case of an AHL/ALC failure, I guess to notify the driver of a fault (Check Low Beam error).

https://xoutpost.com/bmw-sav-forums/...questions.html

BTW, I have an extra ALC module I believe lying around somewhere that I bought for testing. You are in Austin and are welcome to it (lol if I can find it).

[jeffmiller]

Originally Posted by crystalworks

Proceed below:

Swap your headlight from left to right... the plugs fit both lights. That will eliminate the LCM as an issue.

You already swapped tried xenon bulbs, so no need to test those.

Then, swap the ballast from the working light to the non-working light. If it fixes... you need a ballast.

If not, swap ballasts back to original and swap the AHL/ALC (I always forget which the late models use vs. the early ones) modules under the headlights. Inspect the non-working on for corrosion while doing so. Clean with CRC electronics cleaner if any present. If no change in behavior swap the AHL/ALC modules back to original.

At this point it gets tricky because you might need INPA (or ISTA) to reset the AHL/ALC setup. I experienced your exact problem and it ended up being my AHL/ALC module on the driver's side headlight had gotten water intrusion in it. I replaced it with an ebay one of same part number (cost was very cheap ~$50). But it would still not work... UNTIL I reset the AHL/ALC in INPA.

There is a workaround... which I had to use while I was figuring all of the above out (and getting INPA/ISTA install to work) in order to drive the X5 at night. I describe that in the thread below. Basically it piggy-backs the working headlight because the LCM disables voltage to the low-beam in case of an AHL/ALC failure, I guess to notify the driver of a fault (Check Low Beam error).

https://xoutpost.com/bmw-sav-forums/...questions.html

BTW, I have an extra ALC module I believe lying around somewhere that I bought for testing. You are in Austin and are welcome to it (lol if I can find it).

Will try thanks! the thread you referenced sounds like my exact problem!

[X5chemist]

Hey, you're in Austin. I have a set of headlights I plan to clean up and swap in. You can borrow them to test wiring. Only the bulbs are missing. The bulbs have been installed on my current driving set. The same side burned out two bulbs. I realized cracked sheathing burned them after a close inspection. Open wires would touch each other while driving.

[jeffmiller]

Originally Posted by X5chemist

Hey, you're in Austin. I have a set of headlights I plan to clean up and swap in. You can borrow them to test wiring. Only the bulbs are missing. The bulbs have been installed on my current driving set. The same side burned out two bulbs. I realized cracked sheathing burned them after a close inspection. Open wires would touch each other while driving.

Thanks man! I'm going to try the headlight left/right swap first (unfortunately it's a bumper removal situation to get those headlights out).

I'll drop you a line if I get to a spot needed some known-good units.

[crystalworks]

Originally Posted by jeffmiller

Will try thanks! the thread you referenced sounds like my exact problem!

No problem. Let me know if you want the ALC module.

If you swap the headlights and your bulb still does not work, it's likely that the LCM has to be reset using INPA or ISTA like mine did.

Or you can do that workaround in the thread.