Momentary vs Constant Brights - Wiring??

S

StudioWizard

Member
 Los Angeles, CA, USA
I recently had some new headlight assemblies installed on my 2005 2.5i. The brights work when the lever is pulled back (momentary mode), but not when pushed forward (constant mode). I believe the original lights worked fine in constant mode meaning I don't think there's anything wrong with the lever. To be sure, though, does anyone know if there is separate wiring for the constant vs momentary brights?

I would think that there wouldn't be separate wiring - that it's simply a mechanical function of the same switch, but what do I know?
 
The switch simply sends signals to the LCM which controls the actual bulbs. Are they a straight swap - halogen for halogen or xenon for xenon?
 
The entire headlight assembly was replaced. I believe they are the 2Xcite marketed under the OEMassive brand. The bulbs are halogens...
 
I'm sure the originals were halogens... they were the original lights for the car. I bought the car AFTER the lights were replaced.
 
Btw, I stopped by a mechanic today (master technician) who said there's a sensor on the upper part of the windshield (connected to the rear view mirror) that controls the brights. He said he's pretty sure that's why the brights won't stay on in constant mode. Hmmm.... so confusing.
 
I always question mechanic's that call themselves master technicians; high beams are nothing to do with sensors on cars of this age. Newer ones with "intelligent" headlights that adjust to oncoming traffic, yes, but not an E85. The only sensors are rain and auto-dipped beam on the windscreen and door/rearview mirror tinting on the mirror itself.

The only scenario (apart from dickie switch) I can think of that fits is if the car is expecting bi-xenon HIDs where flash is a halogen bulb while constant high beam is mechanical shutter plus dipped xenon. Do you have the headlight height adjustment wheel on the light control module?
 
I did take out the dome light and there is a set of wires in that mirror mount area in addition to the dome light wires. But, I agree: I don't know what that would have to do with the brights much less why it would only affect the constant vs momentary switching. It's a very annoying puzzle.

The actual lightbulbs in this car are not xenon or HIDs - just halogens and whatever the high-beams would normally be. The light is very "incandescent" looking when on.

When the momentary brights are on, should the low-beams also be on?
Is it the same or different when the constant brights are on?
My recollection is that momentary vs constant have a different combination of low-beam/high-beam on/off.

As for the "master technician" part, he showed me a certificate mounted in his counter. His shop does get very good reviews and he was highly recommended by someone I know. But who knows?? The whole master technician thing could be BS.
 
smorris_12 said:
Do you have the headlight height adjustment wheel on the light control module?
Click to expand...

I do have a wheel on the LCM, but that controls the dashboard/cluster light levels - basically a dimmer. Are you saying some Z4 headlights height can be adjusted from inside the car? I've never heard of that nifty feature, but I am a newbie, so.....
 
StudioWizard said:
smorris_12 said:
Do you have the headlight height adjustment wheel on the light control module?
Click to expand...

I do have a wheel on the LCM, but that controls the dashboard/cluster light levels - basically a dimmer. Are you saying some Z4 headlights height can be adjusted from inside the car? I've never heard of that nifty feature, but I am a newbie, so.....
Click to expand...

This is an LCM for a car with Xenon headlights. Seems like smorris is on the money with thinking your car had, at one point, xenon headlights.
 

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That's what my LCM looks like except just one button for the fog lights.

That dial is just for the interior dash lighting, though.... What are you saying is the headlight adjustment?
 
I can't help you any further bit it seems like you have the wrong LCM for the headlights you currently have.

Hopefully smorris will be back in a bit to give better advice.
 
Usel said:
I can't help you any further bit it seems like you have the wrong LCM for the headlights you currently have.

Hopefully smorris will be back in a bit to give better advice.
Click to expand...

I did some poking around on original equipment for 2005 2.5i and I think you're right that it needs Xenon bulbs. I really appreciate your help! I'm brand new to this, so I'm learning... and really enjoying it!! I never realized how much fun BMWs are.
 
StudioWizard said:
Usel said:
I can't help you any further bit it seems like you have the wrong LCM for the headlights you currently have.

Hopefully smorris will be back in a bit to give better advice.
Click to expand...

I did some poking around on original equipment for 2005 2.5i and I think you're right that it needs Xenon bulbs. I really appreciate your help! I'm brand new to this, so I'm learning... and really enjoying it!! I never realized how much fun BMWs are.
Click to expand...

Well hopefully someone with more expertise will confirm but it could be as simple as spending £40 on a second hand LCM but it will need coding to the car.

Where in the UK are you as someone may have one and they may be able to code it to your car for you.
 
I'm in the US! haha

FYI: The momentary and constant brights worked just fine prior to replacing the headlight assemblies. The original ones were terribly fogged up and always had condensation inside - they were a mess. haha I was originally renting this car and I left the constant brights on all the time until they replaced the headlight assemblies.
 
Go me. On the head. Five points to me!

The light control module (LKM) would have 2 wheels for a halogen setup. Have a Google and you'll soon see the difference. In Europe HIDs have to be self leveling to compensate for any extra weight in the trunk, hence the absence of the manual adjuster.

Anyway, they've replaced HID headlights with ordinary halogen units (because cheaper) which, if you drive at night, you'll soon regret. If you have any leverage over the people that did the work, ideally go back and make them put HIDs in.

If not, then all is not lost. Since the high and low beams are being powered correctly, the only thing needed is to reprogram the LKM to behave as for a halogen setup. With an appropriate lead and NCSexpert (or possibly other bits of software) the coding options can be tweaked. I can't list exactly which ones, but I've seen them in passing when I've read them out of my LKMs.

If you head down this route then there's loads of info out there. Don't limit yourself to the Z4, it's the same units and settings in E46 3ers, E53 X5s, E39 5ers, etc
 
I'm so lost!!! haha I have no idea how any of this works.... I don't think these lights have any capability of adjusting their directionality in any way. They're just fixed lights. The originals, as far as I could tell, were the same - just fixed/non-moving parts.

Am I missing something?? haha (I'm sure I am.)
 
If the original lights were xenon then you would need to re-code the lcm to halogens. Does the high beam light come on the dash when you push the lever forward?
 
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