View Full Version : Cadillac CTS LED MODS

11-07-11, 01:50 PM
Hey team, for all of you that have clear fogs and hate the amber bulb, this is for you. There is a new led called switch backs that are hyper white as drl's and when you signal they turn amber! Now that's cool. I've pretty much converted the whole car to led minus my high beams. I haven't released any photos of my car yet because I want to wait to get it closer to that perfect look. But the the pix do come out....whoa stand back!

11-07-11, 03:22 PM
Hey, those LEDs sound interesting, do you have a link to the ones that you are talking about?

11-07-11, 04:29 PM
and hurry up with those pics : )

11-08-11, 08:29 AM
just go to v-leds.com and find them there...I'll also be installing them when I get my clear foglights.

11-08-11, 01:27 PM
Can't use the switchbacks.

The CTS uses the high side of the turn signal for DRL's. On the switchbacks, those are amber.

When the CTS blinker is on, it cycles the high side on and off.

So, using the switchbacks in this application will only result in it being amber all the time.

11-09-11, 04:30 AM

11-09-11, 05:59 PM

Of what?

01-10-12, 06:58 PM
I am wiring up my switchbacks to work properly this weekend.
DrSpeed is right, popping in plain switchbacks do not work. They stay amber all the time.
To have the true clear to amber to clear again switchback you must have a 3-wire harness at the 3157 bulb but our V's only have 2 wires so they do not funcion as intended.
I have wired up a relay for each side that allow them to switch. I have to make another run to the parts store to buy a 3 wire harness then I will get around to installing them this weekend.
It works when I bench tested it so hopefully I can get them to work in the car as well...

01-11-12, 09:29 PM
If it works, make more harnesses and sell them. ;)

01-17-12, 12:54 PM
The tough part is that you need to pull the DRL signal from waaay upstream, prior to the turn signal output.

Looking at the turn signal relay, it looks like it's all built in to the relay. You can do this without a relay if you:

a. Disable the DRL by clipping the pin
b. Get the 3 wire 3157 connector (may be able to get them from the salvage yard from the GM tail lamps)
c. Connect the existing ground and turn signal wire to the original locations
d. Provide a seperate (switched if you want) key on hot wire to the low side of the harness, so it is powered when you have key in the RUN position.

No relays needed, since the LEDs pull such low current. May want to use a fused power source.

01-21-12, 01:42 AM
You are correct again DrSpeed and thanks for your input/ideas.
I realized the relay setup was gonna be too much of a hassle and may not of even worked.
I'm still messing with it but what I have done as far as quick testing has worked fine.
I found a spare connector and pulled the pins out of it it re-pin mine.
There are three pins needed to power the switchback bulbs properly.

(negative - DRL - turn signal)

The V's look like

(negative - empty - DRL/turn signal)

The turn signal wire has priority in the switchback's circuit which means that it lights the amber LED's even when the center DRL pin still has 12 volts.
Our cars use only the outer two pins though. I took the V's outer DRL/TS pin and move it to the center position so that the DRL output powers the clear LED's.
I then added the extra pin I had to the outer spot.
I ran a temporary wire with a diode in line from the right rear 12v turn signal output up to the new added pin on the right front harness.
So essentially the previously existing 12v wire powers up the DRL/clear LED's and when the turn signal gets activated it pulses the 12v's to the center and right pin causing the amber LED's to take priority.
This results in the turn signal flashing amber as intended.
I will search the car for an easier way to get the turn signal output without going all the way to the back of the car. Hopefully I'll find one...
It is in hibernation now but I'm gonna spend some time with her this week to figure it out...

01-24-12, 01:39 PM

If you do the DRL disable mod (Cadillac FAQ), and find a key on hot, and run that to the DRL pin on the connector, that will be your NEW DRL signal wire.

The existing DRL/Turn Signal wire is now just the turn signal, because the DRL has been eliminated.

So, intead of running wires from the tail lamp for a signal, your existing wires provide the new signal, and you simply need to run two new wires to each of the connectors to provide the 12V needed for the NEW DRL signal wire.