Help! LED Light Questions

[agwondra]

I know several people on the forum have switched out the factory bulbs for LEDs, and some have even posted the bulbs they used and posted picutures. All the bulbs are pretty easy to source except the DRLs. Thank you very much for sharing.

Has anyone switched out the 3757 bulbs for LEDs?

Does a regular 3157 Amber LED work?

Does it require a resistor to function properly?

If so, what is wattage and ohms of the resistor used?

I have been told by 2 LED suppliers that the switchback (white/amber) LED bulbs will not work in the XLR. Just wondering if anyone has been able to make them work. It seems like such an elegant option...white DRL and an amber turn signal when needed.

I know some have experienced the frazzeling of the DRLs by the hot bulbs, and I was wondering what you have done to correct the situation. I know this may be blasphemous since most of us try to keep the cars stock, but has anyone used the aftermarket DRL/Turn Signal LEDs? If so where did you mount them?

My apologies if this information is somewhere on the forum, I have been unable to find it.

Thanks for any assistance and sorry for the long post.
Al

[HOMEGAMEROOM]

I replaced mine a few years ago. Yes, I did need a resistor - I don't remember the wattage of it. My complaint is that my amber LED replacement (front DRL) isn't nearly as bright as the regular incandescent lamp (and I've tried a few different types of LEDs).

The socket for the DRL is a little odd - you may have to fiddle with the LED leads and/or base to get it working, but it isn't too difficult to figure it out.

PS I only fiddled with the LED lamp base and NOT the socket!! Good luck, and let us know if you find a nice bright amber LED!

[onalaska]

I put V-Leds 3157_92_WA2_5K in for the turn signal / DRL bulbs along with 6 ohm 50W 2 bulb resistors so the turn signals will function normally. The switchback feature does not work as the XLR only uses one filament of the 3757 bulb so I only have amber turn signals and amber DRLs like the factory bulb. Basically the XLR keeps a single filament of the amber bulb powered for the DRLs and then pulses it for a turn signal. I found that out after I bought the LEDs and also found out that the amber portion of these LEDs will burn out if they remain illuminated for any length of time so I definately would not recommend them for this application. They are very bright as turn signals. To work around this problem I turn the DRLs off everytime I start the car and just use them as turn signals. I plan on changing the sockets if I can find a dual filament socket and then wiring the 5K white portion of the LEDs to the parking lamp circuit so they will be on with the parking lamps. This would still require the DRL's to be turned off every time I start the car, but I am use to that.

[agwondra]

Thanks for the update and the information on the resistors required.

Has anyone found an LED that will work for the DRL function?

Does anyone know why the Cadi engineers would specify a dual element bulb and then use only one of them for the DRL/Turn Signal function in the car?

[agwondra]

Here is the information I have on LED replacements for the incandescents that come on the car.

Location fficeffice" />>>	Qty >>	OEM Bulb >>	LED Info>>
Rearview Mirror>>	2 >>	194>>	194 – forward facing leds>>
Under Dash >>	2 >>	194>>	194>>
Glove Box >>	1 >>	194>>	194>>
Center Console>>	1>>	194>>	194>>
Door Courtesy Lights >>	2 >>	194>>	194 – requires ½ inch instrument panel plug>>
Front Side Marker >>	2 >>	194>>	194 – forward facing leds>>
Back-up/Reverse >>	2 >>	3156>>	3156>>
License Plate >>	2 >>	2825LL >>	194 – forward facing leds>>
DRL >>	2 >>	3757>>	3157 - Amber>>
Front Parking >>	2 >>	3157>>	194 – forward facing leds>>
Front Turn Sig >>	2 >>	3757>>	3157 - Amber>>
Trunk >>	1 >>	PC168 Any WLED series or 194 style>>	194>>
Hood >>	1 >>	Rigid Loop Festoon 44 x 10.5mm>>	> >
HID>>	2>>	D1S>>	N/A>>

Would like to add the information for the vanity mirrors if anyone has it I will update the list. I used 'forward facing' when I have all of the emitters on 1 side of the bulb opposite the base.

[XFireXLR]

I am in the process of ordering the switch back LED turn signal bulbs and I was assured that the bulbs will work in our cars, and if not I would get a full refund. Once I receive them and get them installed, I will post the results.

[agwondra]

Originally Posted by XFireXLR

I am in the process of ordering the switch back LED turn signal bulbs and I was assured that the bulbs will work in our cars, and if not I would get a full refund. Once I receive them and get them installed, I will post the results.

I think I may have figured out why the 'switch back' LED bulbs do not work with the XLR. I think both the DRL and Turn Signal use the same element of the bulb (the lo element). The control module energizes the element for the DRL function whenever the car is taken out of Park (unless the driver turns the DRL off). Whenever the Turn Signal function is engaged or the hazard flasher is engaged the control module periodically interrupts the DRL circuit and makes the single element flash. If the DRL is off by either driver choice or by having the headlights on, the control module energizes the circuit to make the bulbs flash as needed.

If I understand the 'switch back' bulb it is a standard dual element design (3157) with the lo circuit the 'white' set of LEDs and the hi circuit the 'amber' set of LEDs. The bulb has some form of limiter to turn off the white LEDs whenever the amber circuit is engaged. Since the XLR appears to use only 1/2 of the elements in the 3757 bulb the switch back will never know to activate the amber LEDs since the hi element does not appear to be used by the XLR circuitry. At least that is my theory on the operation.

[agwondra]

I had the XLR into the shop yesterday to change the differential fluid (rear end was slipping in tight turns). I decided to stop in the parts dept to find out what bulb was used in the vanity mirrors. I still want to replace mine w/LEDs. It appears that for all new Cadillacs starting with the XLR in 04 if a bulb burns out in the vanity mirror on the sun shade, the entire sun shade needs to be replaced. The bulbs are no longer intended to be a servicable item.

[jjsea55]

Hmmm, that's interesting... but not totally surprising. I've changed out all the other interior bulbs, but have practically decided that LEDs in the vanity mirror may be too bright for our tired eyes .

[agwondra]

Well I have completed the replacement of all incandescent lights w/LEDs. I used the chart I supplied to replace all interior and exterior bulbs with LEDs. I have also replaced the Fog Lights with H11 7.5w 6000K LEDs. They are as bright or brighter than the OEM bulbs and they now have the right color temp. I tried to add LED switchback LED strips at the bottom of the HL assembly but 2 sets of strips have proved to be defective w/portions of the LED strip not lighting. Perhaps in the future.