[WagonsForever]

I do a lot of driving on backroads at night and also used race pro-rally so lighting is important to me. Sadly, my CTS is a model that came with halogen headlights so I’ve been looking into ways to improve on that. The two most logical ways to go are to convert to LED or HID. I’ve spent quite a bit of time researching the choices and finally decided to do the logical thing and buy both. I purchased them from Headlight Experts (who I am not endorsing, but seem to be among the more reputable conversion companies). It took months and several emails to get the HID kit delivered. I ordered all the options so with the 35W canbus and the warning cancelers the H11 kit came in at about $110. So far so good. I also bought aftermarket replacement headlight assemblies because mine were getting foggy and if modifications were needed I didn’t want to chop up the factory units. (more on this later) Some bench testing proved that the light was indeed brighter – and purer white than the yellowish halogens – but thankfully not bluish like the over 6000K units produce. The pattern was good too, with a sharp cut-off so as not to be offensive to oncoming traffic. Also, 35W is plenty. I think going to 55W is just looking for trouble.

Speaking of trouble, there is absolutely no way the conversion HID bulb assemblies will fit into the low beam location in the CTS headlight assemblies. I called the “experts” and they said “most people just leave the access covers off” which sounded like a terrible idea to me. Another concern I had is that the low beam lights on the gen 2 CTS also function as DRLs. – and - maybe one of my CTS brethren on the forum can confirm the rumor is that they run at something like 9 volts in the daytime to prolong bulb life. I should say here that prolonging bulb life is a good idea because you have to take the whole front end apart to change the bulb. (The dealer gets $350 for it …. Plus the bulb … of course). I also have no idea what happens when you try to run the HID ballast on 9 volts, not to mention finding a place to mount it and the other little boxes in the harness.

OK fine. The LED kit will solve all my (admittedly self-created) problems. They’re $110 with the warning canceler. I’m a bit Leary of LEDs for a headlight application (it’s not what God and Thomas Edison intended) and because it’s still kind of an emerging technology. Heck there’s moving parts for cryin’ out loud! Little bitty fans stuck to the back of the bulbs, um, I mean “Emitters.” How reliable can these things be if they need fans to keep ‘em from burning up? Yeah, I knew this going in but still… Oh and another thing – they don’t fit inside the headlight assembly either. Closer, but no cigar. (See photos) Even so, the light is pretty good, an improvement over halogen and good beam control too however the website claims of 3 times brighter light are ridiculous. Am I willing to butcher the brand new headlight assemblies to shoehorn these things in? Of course! My brothers and sisters on the forum need to know! Well OK maybe not, but I’m doing it anyway.

By comparing the standard H11 bulb to the LED unit, the additional clearance needed is around half an inch

Standard H11 bulb

LED Conversion “Bulb”

This can be easily achieved by cutting out the center of the access cover and gluing in an “extension” created by chopping off the top of a plastic chicken bullion jar. I am not making this up.

I have heard, but can not verify, that this will also work on sedans.

Using a drill press and circle cutter set to the OD of the jar threads and securing the cover to a block of wood the cover can be cut as shown. I make no claims about the safety of this procedure. It could probably be done with a hole saw or even by hand with some determination and a coping saw, but this worked for me.

Cutting the access cover with a circle cutter

Cutout complete

Enter the bullion jar. Just cut the top section off so that the threads and “shoulder” are all that’s left

Cut off bullion jar

Test fit the jar top in the hole

Jar top inserted in cover "inside" view

Outside view

Showing clearance for LED unit

Final modified access cover. (Note red jar lid for right side and blue for left)

Once everything is test fitted, glue the whole wretched mess together with a good quality adhesive. I use a product called Seal All, but stuff like E6000 will work fine. Probably don't use silicone, I'm not sure it's strong enough. Put the glue on the outside of the jar threads, screw the lid on and also create a fillet between the jar lid and the outside surface of the cover. Make sure the lid and cover are completely sealed to maintain the integrity of the headlight assembly. Let it completely dry for a day or so before mounting to the headlight assembly in case there is any outgassing (who knows how it might affect the LED emitters?) This also provides an opportunity to show off your handiwork to people who could care less and think you're crazy for doing it.

Modified cover in place on headlight assembly

Although I see no reason this can’t be done to factory assemblies as well, the use of aftermarket ones (I used PERDE units SKU:GM00529-HLAP) allowed me to be messing around with this foolishness while still having a drivable car. I also installed PERDE Solar Series Platinum H9 Xenon-Enhanced Halogen Bulbs in the H9 high beam position as long as I had everything apart (SKU:H9-65-BX2)

I still plan to add fog lights as described in the excellent post from rspreng on Feb 11, 2013 but for now at least I have somewhat improved lighting. Was it worth it? Well, it was to me, but not everyone is a picky about lighting as I am. Regardless, I hope some folks found this post interesting. Thanks to all of you for providing and contributing to this invaluable resource.

 

[Lifespeed]

Interesting! Where are the LED fans, sealed inside? Will the plastic jars distort and fail from the heat? Are the high beams halogen and the lows LED?

 

[Long]

@WagonsForever excellent write up
Please update the thread after some time/use for the group.

 

[WagonsForever]

Interesting! Where are the LED fans, sealed inside? Will the plastic jars distort and fail from the heat? Are the high beams halogen and the lows LED?

The fans are in the finned aluminum housing that sticks out the back - you can see it best in "Showing clearance for LED unit" photo. I have no idea if the jar lids will hold up, but I'm betting there isn't that much heat generated. It didn't seem like much in the bench testing.

I left the high beams halogen but upgraded the bulbs as listed. On a side note, the high beam area in the assembly has way more room in it and will accommodate any mods I'm sure - I thought about using the leftover HID kit there but - HID requires a warm up period (even though it's only a few seconds) - so not really suitable for "flash to pass" use but probably awesome for backwoods blasting.

 

[WagonsForever]

@WagonsForever excellent write up
Please update the thread after some time/use for the group.

Will do. It's good to be back. I'm also thinking of using the "leftover" HID kit in my future fog light addition since they use H11 bulbs also.

 

[Padgett]

The little fans are why am avoiding LEDs for the moment, if they fail what happens ? If takes out the housing is many $$$. Am happy with the HIDs in my CTS and have Silverstar Ultras in rest of herd.

 

[Joseph Upson]

The fans are in the finned aluminum housing that sticks out the back - you can see it best in "Showing clearance for LED unit" photo. I have no idea if the jar lids will hold up, but I'm betting there isn't that much heat generated. It didn't seem like much in the bench testing.

There's a lot of heat generated, so with the fans enclosed in the housing the cooling efficiency will be reduced since they'll be circulating previously warmed air, adding more heat to it. Cooling fins and a fan are a bit much to be mostly for show.

I have some assorted LED chips and courtesy bulb replacements and the wafer chips they are attached to get extremely hot when illuminated continuously by a 12v source and are guaranteed to burn when handled carelessly. I like the creativity and ingenuity demonstrated in your setup.

 

[redheadedrod]

I have LED's in my fogs. They work well in that application. The issue with LED's in normal bulb configurations is due to the fact the LED light comes from a square. This focuses the light into hotspots infront of you. Any diffusion of the light ends up being glare to other drivers and is of very limited use to you as the driver. So the use of them as replacement headlight bulbs is of limited usage. Some LED's are a little better by using more diffused outputs. But realistically, unless you have a projector that focuses all of the light in front of you it is hard to find an LED that works as a headlight bulb. This is where HID's are much better. You don't get the glare of the LED's but they are generally just too damn bright to be used all of the time. You need to put them into projectors so you can limit the height of what they put out so you are not blinding other drivers.

In fog lights the lense disperses the light out to the sides more, they start out lower to the ground and any hotspots are not as big a deal. I use the LED's as fogs and they are about the only thing that gets brighter than the headlights. I have had to drive using foglights only during major snow storms. The one we just had about a month ago was one that with the normal HID lighting (And would have been WAY worse with LED lights in a normal bulb housing) I was lighting up the snow in front of me and not the road and could not see anything. I turned off the headlights and only ran the fogs. I was able to see down the road decent, although not as well as I could with the headlights without the snow falling, but I was able to maintain a decent speed and still see everything.

 

[Padgett]

I set fogs to light up the side of the road in poor visibility. Still do not care for anything the relies on a mechanical fan to protect plastic housings. I keep spares for desktop computers when they fail but will tell me.

 

[Lifespeed]

I set fogs to light up the side of the road in poor visibility. Still do not care for anything the relies on a mechanical fan to protect plastic housings. I keep spares for desktop computers when they fail but will tell me.

Cooling fans and their (lack of) reliability are a concern.

 

[WagonsForever]

If I knew then (when I bought my CTS wagon) what I know now, I would have really focused (pun intended) on the models with HID lighting. I’m pretty sure those are the ones with factory fogs also. Oh well, … live and learn. I’ve been following LED lighting for years and use them exclusively in my shop, but always been skeptical of headlight applications (still am – but I’m willing to be the “guinea pig” here). I think the point redheadedrod makes about needing a projector that focuses the light in front of the car is critical. As it happens, the lower trim-level halogen equipped models do in fact have projector type low beam lenses – so at least there’s that. But how the little flat stick with the tiny square “emitters” on it was gonna work with the projector / reflector assembly designed for a halogen bulb, I had no idea. Bench testing was promising, but until you actually drive it, you don’t really know. The point of this whole ridiculous modification was to see if I could improve the lighting after missing out on my first choice which should have been factory HIDs.

Frankly, I was pleasantly surprised at the results (see photo below). The sharp cut off was very encouraging (and essential, to avoid rain / snow glare) and the beam pattern didn’t have voids or hot spots. The color is pure white – (like maybe 5000K? and not at all that goofy blue I was hoping to avoid). Also, the LEDs are in fact, noticeably brighter (maybe "crisper" is a better description) than halogens but not to the point that they’re offensive to oncoming traffic when aimed properly.

Of course, there’s still the heat and reliability concerns that only time will tell about and I’ll keep the forum posted on that, but my general assessment is – so far so good.