996 LED Headlight Bulb Upgrade

March 3, 2019 - General
996 LED Headlight Bulb Upgrade

I had always felt that the factory headlights weren’t the best, as they were the non Xenon units. Considering the type of car I was surprised at their somewhat lacklustre performance and despite trying ‘upgrade’ brighter H7 halogen bulbs they made little difference, so decided after far too long that a proper upgrade kit was in order.

Having looked at both Xenon and LED upgrade kits I decided to look at LEDs as they are the more modern choice. Eventually after much research (manufacturer information, videos, web info, Philips’ excellent online customer support) I settled upon the Philips X-tremeUltinon LED gen2 H7 kit. Probably one of the most expensive LED kits on the market, but boasting premium Lumileds LUXEON Altilon SMD LED chips as used by car makers and Air Cool heat management. Philips X-tremeUltinon gen2 is the only aftermarket retrofit LED using Original Equipment Manufacturer (OEM) LED chips according to the Philips website. It would appear you do get what you pay for….. more later.
It is worth noting that these Philips LED bulbs are not ECE approved for road use (likewise neither are aftermarket Xenon kits) so technically they shouldn’t be used on road.

Additionally the driver pack is very small measuring 58mm x 19mm x 30mm, smaller than the Xenon ballasts I could find and the heatsink assembly is one of the shortest around, another important consideration given that there is limited space inside the 996 headlamp unit and I did not want to cut the rear cover. Making sure there is enough space behind where the bulb locates is important to ensure the heatsink fits and the unit cover fits and closes to keep the unit air and water tight.

So here are the bulb images, courtesy of the Philips website:

And here is the full kit for one headlamp and also the dimensional diagram which Philips supplied prior to purchase so that I could check I had enough space for the units:

The picture of the bulb and driver (above right) shows the OE H7 bulb holder fitted to the bulb. Note that this bulb holder is applicable to 2002 onwards non Xenon headlight units.

So with the LED bulb’s heatsink assembly measuring just 30mm, there was enough clearance behind the original bulb for this to fit. The original wiring plug assembly measures around 20mm, so the LED bulb only protruded an extra 10mm. The OE H7 bulbs are fitted into a bulb holder (Porsche Part: 99663112800/Hella 155977-00). This holder needed to be used to correctly locate the LED bulb and fit it into the headlamp housing. However it is not a direct fit onto the new bulbs sadly, so some slight modifications were needed. I believe early pre-2002 lights use the more traditional metal spring clip to retain the bulb into the unit, but don’t quote me on this!

I bought 2 new plastic bulb holders which were a little under £8 each. Don’t moan, Saab (P/N: 93188670) want £25 for the exact same thing (even has the same Hella number on it)!! The new locating rings were modified and I kept the original ones back in case I ever want to return to standard, meaning the upgrade is fully reversible.

Here are the OE retaining rings/bulb holders pre tampering:

First you need to carefully snap out the clips from the holders, shown top and bottom in above images. These clips are what locate the OE 2 pin wiring plug into the holder. You end up with the below:

Then using a Dremel or similar carefully remove the remaining plastic until flush with the surrounding area (red arrows below left image). Then using a small file flatten slightly (it doesn’t need a lot) the rounded pieces at either side (green arrows). These tabs will sit snuggly at the base of the LED bulb, so check and file carefully until you have just enough clearance. Note the Blue arrow is the tab to allow correct bulb alignment. The tab on the bulb aligns to the left of the tab identify with the blue arrow.

Finally turn the holder over and again using the Dremel remove some plastic from the front of the holder above where the 155977-00 is (red arrow shown above right). This will give some additional clearance for the main wiring coming out of the bulb when the holder is fitted to the bulb.

You should end up with something looking like this:

Now for fitting…..

First remove the headlight itself from the car. Carefully pull back the carpet trim, remove the rubber bung and using a 5mm deep socket and handle (or the OE removal tool) rotate the retaining bar and pull the light unit clear. Remove the rear cover to access the dip beam bulb. 2 clips each side at the top, press them and drop the cover backwards and off. Identify the dip beam (top bulb). Rotate the holder to the left and remove the bulb, holder and 2 pin wiring plug.
For reference it is worth noting the orientation of the original bulb in the holder when you first remove it. The metal tab on the bulb (marked in yellow) aligns to the left of the tab on the plastic bulb holder (marked in blue) when viewed from the front and when fitted this is at the bottom.

Carefully pull the bulb from the 2 pin plug, then unclip the 2 pin plug from the OE bulb holder by lifting the retaining tabs.

Now to fit the modified bulb holder to the Philips LED bulb. First unscrew the heatsink assembly anticlockwise from the bulb. Be careful not to touch the leds. Then fit the modified bulb holder onto the rear of the LED bulb. As with the halogen bulb align the metal tab (yellow arrow below) up to the left of the tab viewed from front (blue arrow below also shown in one of the above pictures) and make sure the holder is touching the base of the bulb and the bulb is sitting flush with the holder. Now, screw the heatsink back onto the led bulb. You will need to ensure the main power cable is held out of the way and screw the heatsink on tightly so that is tightens down onto the holder securely. You will need to manipulate the power lead to the bulb so that it pushes as far back as possible into the holder and clears the heatsink as you screw it back onto the bulb.

Once assembled the bulb can be fitted into the light unit. The LED bulb must be fitted so the bulb is vertical and the LEDs are on the sides. The LED bulb can be rotated if needed, there are degree markings on the front, however it should be orientated correctly if set to 0 (as out of the box) and correctly located in the bulb holder. With the single tab pointing down at about 5 o’clock and the two upper tabs at 9 and 1 put the bulb into the assembly and rotate clockwise until the holder click in place and the tabs are then at 6, 10 and 2 respectively. When first inserted the bulb is slightly off vertical and orientates correctly as the holder is twisted clockwise into the light housing and located with a click.
Now the driver wiring can be connected to the bulb and heatsink, tightening the securing rings and then cable tied out of the way together. The driver itself can be fitted in the space at the base of the light unit secured with a small piece of double sided tape and then the 2 pin driver plug connected to the OE 2 pin plug. Ensure correct polarity, with the + on the 2 pin driver plug going to the yellow wire in the OE plug. Ensure the wiring clears and doesn’t rub anywhere. Finally the rear cover can go on and the headlamp can be refitted to the car.

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