DTS front lighting upgrade to LEDs

**ogbuehi** · 02-03-12 08:46 PM

So I've finally received all my led bulb equivalents for the parking lamps, drl's, fog lights, and cornering lamps. I decided to get a head start and start work on this project this evening. So far I've done all the top end work, and removed the wheel liner so that I have access to the cornering and fog lamps. It has been a pain so far but progressed steadily thanks to the service manual. I can say that upgrading the cornering bulbs to led was worth it. I will post pictures of the difference once I get on my computer. But I have run into a problem with the fogs. The led bulb is just barely too big to fit through the housing. I haven't decided if it's easier to grind the edge of the bulb or try to modify the housing. I would really hate to have to go through all this just to do it again later if I got another one. Tomorrow I will attack the parking lamps and drl's. Again, I will post before and after pictures of each bulb type showing the difference between the filament and led bulbs.

**Superjim** · 02-04-12 08:32 AM

I am looking forward to this...
I would like brighter fogs and cornering lights also...

Texas Jim

**ogbuehi** · 02-04-12 05:57 PM

Update. I've finally worked the headlamp housing to where I can finally remove the parking lamp and and drl's on one side. Looks like I got bad info on the parking lamp size. The housing itself has plenty of room for a good size bulb, but the opening is smaller. So the ones I ordered are too big. Luckily I had plenty of extra led bulbs from the Deville led project that were smaller and fit great. DRL's fit fine as well but I'm in the process of trying to figure out which side of the bulb housing hots up the turn signal filament. According to the service manual, only 2 of the three pins are used. One to supply voltage or turn signals, and ground. I think that may be incorrect as there are three wires going to the base and there are three connection points in that base. Plus the schematic indicates that the ground and voltage connections on the base are on the same side opposite of each other. Wouldn't make sense since the bulb has the filaments wired on opposite sides of the bulb base (checked with a multimeter). My last result is to check the voltages at the connection points when the drl circuit is energized. Problem is that I think the car has to be running in order for them to come on. With the tires off, I'm a bit concerned about running the engine. This would be annoying if I have to put the wheels back on to accomplish this.

**Superjim** · 02-04-12 09:33 PM

If it is really solid on the jackstands... if you leave it in park where nothing can turn/move...I don't see what it would hurt...

Jim

**ogbuehi** · 02-04-12 10:42 PM

Update 2. After fiddling with the drl socket and my multimeter and not getting the info I needed, I decided to focus my energy back onto the fog light bulbs. I wanted to check how closely my led bulb was oversized to determine if it was possible to grind the edges down a bit. For some reason, all of a sudden the bulb just slipped right into the housing. Apparently the angle needed to be just right. I'm not sure what that angle was because I wasn't paying attention but I did a mental happy dance.

The housing is slotted with three slots that are different sizes and spaced at roughly 120 degrees apart. I'm getting extremely frustrated that the bulb is not going in after twisting it to every combination I thought possible. I even go back to the other fog light I haven't changed out yet to try and "memorize" the locations of which size slots go in which direction. I compare the unused led bulb I have to the fog halogen I've pulled out and after very close inspection, I realize my led fog slots are a mirror copy of the original halogen. I've done some research and I can't figure out if this is because I have bulbs built defectively or if Cadillac has a h10 housing with different specs. Either way I figure my led bulbs are money down the drain and I decide to try something with them. If I break them it didn't really matter anyway since I can't use them for anything else.

I looked at the slots and see that my bulbs barely don't fit by about 1/16" - 1/8". So I decide to cut the slots down to see if I can get it to fit with a pair of dykes. The plastic cuts easily, nicely, and very exact to my surprise. This it made it easy for me to modify the slots exactly as I needed. To my surprise after trying once, making 1 more set of cuts, I got it to go in AND lock AND seal it self just like the OEM halogen.

I tried to take pictures of the difference between the led and halogen I left on the other side, but I think my garage lighting was preventing me from taking a picture where you can really see the difference. Besides, I'm not sure if they even make a led bulb that will fit without modifying it as I have. So I'm pretty sure most of you on this forum will avoid changing it out unless you have some way of guaranteeing that you could get the h10 bulb with the slots in the right location.

But I can tell you that if you only change out cornering bulbs without changing the fogs the lighting will not match as the fogs are brown and the cornering bulbs will be white. I'm pleased with the overall effect of the led fog as they output a white bright light that corresponds with my cornering bulbs light output which is much brighter now as well.

Tomorrow I will attack the drl circuit again to see if I can come up with some solution to determine which wire I will need to deal with. But just from preliminary testing of the overall light output of my led in the drl housing, I'm pleased with the brightness of that bulb and it now lines up with the timing and effect of all the other led bulbs in the circuit. I love being an engineer.

**ogbuehi** · 02-04-12 10:52 PM

Originally Posted by Superjim

If it is really solid on the jackstands... if you leave it in park where nothing can turn/move...I don't see what it would hurt...

Jim

I guess that makes sense. For some reason I keep thinking about idle moving the wheels, but the car is will be in park which means the transmission is disengaged from the engine. I just didn't want cause some kind of crazy errors but I think you're right. Hopefully tomorrow I can finish this up and begin reassembly.

**ogbuehi** · 02-08-12 07:28 PM

Update. Got the parts I needed today for my headlight upgrade. I had planned to wait until this weekend to test my drl circuit. But since I got off a little early I decided to go ahead and do some preliminary testing. I can say I finally have normal blinking LEDs for my turn signals!!! I will begin the work cleaning up the wiring to make it look stock and then the arduous task of reassembly. I can finally see the light at the end of the tunnel.

**ogbuehi** · 02-10-12 08:44 PM

Update. Decided to get a head start on this since I have to work on changing out the oil on my Deville and do some shopping tomorrow. Finished cleaning up the wiring on the driver side and buttoned everything on that side including the wheel installation. Swapped out the fog light, parking lamp, and drl on the passenger side. All the lighting is working perfectly and all I have to do is button up the passenger side bumper, splash guard, put the tire back on, and put on the radiator cover. Should be able finish all this tomorrow evening and I might even be able to take it out for a test drive on Monday if it's not raining or snowing.

**Superjim** · 02-10-12 11:59 PM

Originally Posted by ogbuehi

Update. Decided to get a head start on this since I have to work on changing out the oil on my Deville and do some shopping tomorrow. Finished cleaning up the wiring on the driver side and buttoned everything on that side including the wheel installation. Swapped out the fog light, parking lamp, and drl on the passenger side. All the lighting is working perfectly and all I have to do is button up the passenger side bumper, splash guard, put the tire back on, and put on the radiator cover. Should be able finish all this tomorrow evening and I might even be able to take it out for a test drive on Monday if it's not raining or snowing.

Very good... glad to hear about the progress...

Jim

**creepingdeath** · 02-11-12 11:52 AM

Nice to read about the progress.
I bought some "plasma yellow" fog lights and LED cornering bulbs for my DTS. First I installed the cornering LEDs. The bulb itself was a touch larger than the opening, but was able to cram it thru. Mistake! First, the LED barely lit up anything. Two, when I tried to remove said bulb from housing, it popped off the socket and into the housing it went. 20 min. of noodling around with my fingers, I was able to get the bulb to stand up and then reach in with a needle nosed pliers and grab it and yank it out. PHEW!

Next I installed the fog lights. The ones I received were 9005. The lights I removed were 9055. The only thing different were the mounting tabs, or ears if you will, on the round part of the bulb base. Think of the tabs on the 9005's being at 8, 12 and 4 'o clock positions. 9055's were on the 8, 12 and 3 o' clock positions. Just enough not to slot it right. Anywho, feeling defeated, I plugged the plasma yellow bulbs in and rested them in the housing to see what they look like. Total crap! They should of been called "slightly yellow". Oh well, you get what you pay for, and I didn't pay that much. I was hoping Silverstar would make a bulb in 9055, but alias they do not. I was thinking about buying the 9005 Silverstar and "modding" the tabs myself.

**ogbuehi** · 02-11-12 05:06 PM

Update. I have finally completed my headlight project. I will take try to take her out for a test run on Monday if the weather permits. I will post pics on my next post. I have finally removed all the incandescent bulbs and given the lighting a $50000 car should have in this day and age.

**creepingdeath** · 02-11-12 09:24 PM

Sweet, cant wait!

**5.0 lsc** · 02-13-12 09:22 AM

Originally Posted by ogbuehi

Update. Got the parts I needed today for my headlight upgrade. I had planned to wait until this weekend to test my drl circuit. But since I got off a little early I decided to go ahead and do some preliminary testing. I can say I finally have normal blinking LEDs for my turn signals!!! I will begin the work cleaning up the wiring to make it look stock and then the arduous task of reassembly. I can finally see the light at the end of the tunnel.

Hey, what drls did you use? Would you mind sending me a link? Did you have to use a resistor kit or did the led have built in resistors? Thanks.

**ogbuehi** · 02-13-12 06:07 PM

Even though it was down in the teens today, it was clear skies so the DTS got to stretch her legs after not being driven for 4 weeks. So no issues with any of lighting. Turn signals/DRLs performed just like the stock bulbs did, day and night. So I learned a little tid bit today. In order to turn "on" the DRL's constantly, the car has to be in gear, it has to be daylight, and neither the fog nor the HID light circuits can be energized. So I had to use the parking brake and put it into drive outside in order for me to view the DRL's constantly on. Here are the pics as posted. If the pics don't look that great, it's because I don't have excellent photography taking skills and I used either my cellphone or point and shoot camera as opposed to using an SLR. I did upgrade the parking lamps to LEDs but didn't bother taking pics of the difference between the old and new because the new ones look just like the ones in the thread below.

http://www.cadillacforums.com/forums...-s-2006-a.html

Old cornering bulb

New corning bulb

Old fog on the left and new fog on the right

All fogs and HIDs

DRL's, fogs, HIDs, and cornering

DRL and HIDs

DRLs only