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Discussion Starter · #1 ·
I'm looking into the possibility of upgrading the 25w bi-xenon D5S bulbs to the 35w D3S bulbs. After doing some research, it seems the D5S bulbs have the igniter and ballast on the back of the bulb, while the D3S bulbs only have the igniter; they need a separate ballast. Does anybody know if the D5S bulb can be changed to a D3S if the ballast is added? From what I can tell, the electrical requirements are the same; the big difference is the ballast.

The IIHS review of the 25w headlights gave them a "poor" rating, while they gave the 35w headlights a "good" rating. I realize the 35w rating also took into account the fact that the lights turn while cornering, but the illumination distance, especially in the corners was better with the 35w bulbs.

It's surprisingly difficult to get lumen ratings for Phillips bulbs, but from what I was able to find, it appears the factory D5S bulbs put out 2000 lumens at a color temperature of 4200k. The specs of the D3S bulbs are even harder to find. It seems the standard lumens is 3200 and the color temp is 4150k but I'm not certain that's exactly accurate. The Phillips XtremeVision D3S bulb is supposed to put out the most light at a color temp of 4800k, but the lumens rating is also 3200? They advertise the light output at 150% which should put the lumens at 4800, however they don't actually give a lumens rating on that bulb. Curiously that's also the color temp so maybe that's a misprint but who knows. Even Phillip's own website doesn't give a lot of useful technical information.

Does anybody have a pic (or can take one) of the ballast used by the 35w high performance bi-xenon setup? Hopefully the label is visible with the manufacturer, part number and specs on it.
 

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I would love to get more light!
From the W205 Mercedes C300 LED headlights, this is the only downgrade I can identify by moving to the Giulia.
It isn't a biggie, but it will be nice to have an easy solution like changing a bulb.

Subscribed to this thread!
 

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Someone with the shop manual might reply

i’m very interested in this topic too. Seeing the cost of harvested postcollision parts on eBay gives me a shock when thinking about purchasing the whole assembly.

Would someone who has access to the technical data please chime in on the feasibility of either a modular replacement or the bulb alone.

Thanks,
 

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Discussion Starter · #6 ·
Will you need to change the reflector? I'd think so otherwise you'll be giving other drivers quite a dazzling view.
I don't believe so since the 25w lens is already a projector lens. Upgrading to a 35w bulb should just give you more light farther out and wider. The IIHD testing graphics showed the 35w bulb did a much better job to the side and around corners.
 

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Discussion Starter · #7 ·

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With MacGeek's vast knowledge of Giulias (and likely other Alfas), if we can get MacGeek into an Alexa like device for all info, we could create world peace.
 
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Discussion Starter · #9 ·
The Xenonland site has a pic of the front of the ballast showing the connector:
 

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Discussion Starter · #10 · (Edited)
With MacGeek's vast knowledge of Giulias (and likely other Alfas), if we can get MacGeek into an Alexa like device for all info, we could end world peace.
I don't think you meant "end" world peace, but I would certainly be in favor of ending automotive ignorance. :wink2:

(I don't mean this applies to you!)
 

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It doesn't directly plug into the back of the bulb, since the HID bulb is behind the large round rubber cover (25W version pictured):



The ballast screws into the 3 posts on the left of the light in this photo (that is also a 25W version):

 

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i’m very interested in this topic too. Seeing the cost of harvested postcollision parts on eBay gives me a shock when thinking about purchasing the whole assembly.

Would someone who has access to the technical data please chime in on the feasibility of either a modular replacement or the bulb alone.
In addition to the complete assembly, the following parts are available separately:

- HID bulbs
- mounting tabs
- rear rubber cap
- electronic control units, both the one for SBL+DRL and, if equipped, the ballast
 

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Discussion Starter · #13 ·
It doesn't directly plug into the back of the bulb, since the HID bulb is behind the large round rubber cover (25W version pictured):



The ballast screws into the 3 posts on the left of the light in this photo (that is also a 25W version):

Awesomeness... so the connector that normally connects to the back of the bulb, goes instead to the ballast, and another connector goes from the ballast back to the bulb. In that one pic it looks like there's plenty of loose cable to go to the ballast. Do you have a pic/part number of the cable that goes from the ballast to the bulb?
 

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I don't, as internal headlight wiring is not a spare part.

I do have this picture showing 35W (D3S) HID bulb replacement:



And this one showing ballast removal:



And although this isn't very useful, here's the internal structure of the assembly:

 

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How can you tell which one you have?
 

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There is a thread on the Giulia forums with illustrations and instructions regarding how to update the 25W headlights to 50W.

IIHS primarily complained that the 25W headlights produced excessive glare, otherwise they would have gotten a Marginal or Acceptable rating. It is unclear if that was just an adjustment problem or if there is an optical issue with the 25W headlights (IIHS does not adjust headlights to factory specs, they simply test a car taken off of a dealer's lot as-is). If the glare is caused by an optical issue, increasing the wattage would make the issue worse.

Checking the aim of the headlights is a good first plan in any case.
 

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I don't think you meant "end" world peace, but I would certainly be in favor of ending automotive ignorance. :wink2:

(I don't mean this applies to you!)
Haha, what happens when I post without my coffee.
 

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Discussion Starter · #18 ·
I don't, as internal headlight wiring is not a spare part.

I do have this picture showing 35W (D3S) HID bulb replacement:



And this one showing ballast removal:



And although this isn't very useful, here's the internal structure of the assembly:

Those are very helpful! The ballast removal pic shows what the ballast is connected to, which I assume is not in the housing for the 25w, even though it appears it's the same housing since it has the mounting location for the ballast. Clearly there's an oval sealing ring on the housing and the ballast.

This may prove to be more difficult than I at first anticipated. If the housing assembly comes pre-wired for the 35w, that means there aren't separate parts available, i.e. the connectors and sealing unit. I don't relish the thought of trying to remove and disassemble the headlight housings just to figure out how to connect the D3S bulbs internally with the external ballast.
 

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Discussion Starter · #19 ·
The pic that shows the back of the DS3 bulb shows it's a Phillips XenEcoStart bulb. I found the specs for that which is 3200 lumens +/- 450 lumens, and a color temperature of 4300k. Going up from a D5S bulb which is 2000 lumens, just the factory standard bulb is quite an upgrade. There has to be a way to do this; just need to do more research!
 

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The pic that shows the back of the DS3 bulb shows it's a Phillips XenEcoStart bulb. I found the specs for that which is 3200 lumens +/- 450 lumens, and a color temperature of 4300k. Going up from a D5S bulb which is 2000 lumens, just the factory standard bulb is quite an upgrade. There has to be a way to do this; just need to do more research!
Just be wary of the cars body systems. Headlights these days are so interconnected that swapping a bulb might not work. Especially since the 35W version is tied to the cornering lights. For example, in my Mini Cooper S you can't even turn on the headlights on a bench (stuff I do for work) without the Body Control Module (BCM). The cornering lights require the steering angle input, which might be it's own sub module within the headlight or within the body itself.
 
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