# Disconnecting DRL's



## sciphi (Aug 26, 2011)

No, we've worked around them so far.


----------



## XtremeRevolution (Jan 19, 2012)

I wonder if its the DRLs that are controlled by the e-brake, or if its all of the automatic lighting functions..


----------



## OEM (Mar 17, 2012)

Humm, good thinking. Someone want to experiment? 

Mark


----------



## 20126spdRS (Dec 27, 2011)

OEM said:


> Is there a writeup on this? I know its controlled through the e-brake. Anyone disabled this?
> 
> Mark


if you turn your headlight control to the left once it turns off DRL, it will display on the screen between spedo and RPM DRL disabled


----------



## joewatson86 (Jul 6, 2011)

Here in Canada, turning that dial to the left only turns off the DRL's when you're parked and the car is running. Since DRL's are required (in Ontario anyways), there is no way for us Canuks to turn them off while driving.

This really sucks for any of us wanting to get HID's in any way (PnP, retrofit or new projector housing with seperate HI and LOW bulbs) because the DRL is on the low beam, so they would always be on! Everytime I see some ricer with their HID's on during the day I shake my head but then I realize that I would have that same problem no matter the lighting configuration i choose unless there is a way to bybass the low beam and make, say your turn signal bulbs, the DRL's instead (or an LED strip added on or part of an aftermarket headlight assembly).


----------



## cecaa850 (Apr 9, 2012)

I believe the low beams and DRL's are on the same wire that has voltage supplied by the BCM. I would think that if you wanted to turn them off, you'd have to access the BCM via scanner and see if it has a selectable on/off feature.


----------



## cecaa850 (Apr 9, 2012)

My Cruze isn't scheduled to hit the dealership till the end of this month (it is built though!). Can someone measure the voltage at the low beam bulb when the DRL's are on for me? I would think it would be between 6 and 8 volts. Thanks.


----------



## cecaa850 (Apr 9, 2012)

Nevermind checking voltage, my idea won't work.


----------



## cecaa850 (Apr 9, 2012)

Here's a thought. The BCM uses a signal from the sun sensor to determine if it's light or dark outside. I'm ASSUMING that the resistance changes in the sensor during light or dark conditions. What if you checked the sensor resistance with the sensor covered (night time) and checked it again shining a flashlight on it (day time) to check for a change. If there indeed is a change, you could figure the needed resistance and wire in a resistor. Of course at that point, your auto headlamps wouldn't work and you'd have to manually operate them. Just thinking out loud.

I guess a piece of tape over the sensor would do the same thing, :icon_scratch:


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> Here's a thought. The BCM uses a signal from the sun sensor to determine if it's light or dark outside. I'm ASSUMING that the resistance changes in the sensor during light or dark conditions. What if you checked the sensor resistance with the sensor covered (night time) and checked it again shining a flashlight on it (day time) to check for a change. If there indeed is a change, you could figure the needed resistance and wire in a resistor. Of course at that point, your auto headlamps wouldn't work and you'd have to manually operate them. Just thinking out loud.
> 
> I guess a piece of tape over the sensor would do the same thing, :icon_scratch:


That would also disable your automatic lighting, such as when the lights turn on when it gets dark enough or you enter a tunnel.


----------



## cecaa850 (Apr 9, 2012)

XtremeRevolution said:


> That would also disable your automatic lighting, such as when the lights turn on when it gets dark enough or you enter a tunnel.


As I stated in my thought.


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> As I stated in my thought.


Ah, I misread. I thought you were only referring to automatic DRL lighting.


----------



## Mick (Dec 31, 2011)

I'm going to be plastidiping my sensor like ChevyDerek.


----------



## XtremeRevolution (Jan 19, 2012)

Mick said:


> I'm going to be plastidiping my sensor like ChevyDerek.


Wouldn't that also cause your DIC and radio to be permanently dimmed, as well as your parking lights to be permanently left on?


----------



## Chevyderek72 (May 16, 2011)

Yes it does, but I can't even tell they are dimmed. I can see it great still in direct sunlight. And the parking lights are on but this is the best way I've found so far.

Sent from my DROID X2 using AutoGuide.com App


----------



## XtremeRevolution (Jan 19, 2012)

Chevyderek72 said:


> Yes it does, but I can't even tell they are dimmed. I can see it great still in direct sunlight. And the parking lights are on but this is the best way I've found so far.
> 
> Sent from my DROID X2 using AutoGuide.com App


I'm still trying to find out, what exactly was the purpose of disabling DRLs?


----------



## cecaa850 (Apr 9, 2012)

XtremeRevolution said:


> I'm still trying to find out, what exactly was the purpose of disabling DRLs?


The most common reason I've seen is people running HID's. The low voltage or PWM modified signal tears the ballasts up. They work good with 12-14v, anything else, not so much. Don't know this particular poster's reason though.


----------



## cecaa850 (Apr 9, 2012)

XtremeRevolution said:


> Wouldn't that also cause your DIC and radio to be permanently dimmed, as well as your parking lights to be permanently left on?


Does the Cruze dimmer have a full bright notch like other vehicles?


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> The most common reason I've seen is people running HID's. The low voltage or PWM modified signal tears the ballasts up. They work good with 12-14v, anything else, not so much. Don't know this particular poster's reason though.


Sounds like running a relay harness such as the one I made the writeup for (see my signature) would be the correct way to accomplish that. Not that HIDs in our factory housings are a good idea...


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> Does the Cruze dimmer have a full bright notch like other vehicles?


No. It's a digital adjustment.


----------



## cecaa850 (Apr 9, 2012)

XtremeRevolution said:


> Sounds like running a relay harness such as the one I made the writeup for (see my signature) would be the correct way to accomplish that. Not that HIDs in our factory housings are a good idea...


With your new wiring, are the DRL's getting a full 12v and if so, wouldn't it look like you're running low beams all the time?


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> With your new wiring, are the DRL's getting a full 12v and if so, wouldn't it look like you're running low beams all the time?


The DRLs are getting the full 12.6-14.4V straight from the battery, and yes, it does look like I'm running low beams all the time. I don't suspect that the difference between DRLs and low beams is going to be that significant with regard to distinguishable output in broad daylight. The modification does however allow me to maintain all other function of my vehicle as if it were stock, and improves my lighting in a perfectly legal way.


----------



## cecaa850 (Apr 9, 2012)

XtremeRevolution said:


> The DRLs are getting the full 12.6-14.4V straight from the battery, and yes, it does look like I'm running low beams all the time. I don't suspect that the difference between DRLs and low beams is going to be that significant with regard to distinguishable output in broad daylight. The modification does however allow me to maintain all other function of my vehicle as if it were stock, and improves my lighting in a perfectly legal way.


That makes sense. I'm not a big fan of the way DRL's look. I'll probably keep scratching my pea brain till I find a real solution. I will be rewiring my lights however also. Looks like a good mod and I like to tweak.


----------



## Mick (Dec 31, 2011)

XtremeRevolution said:


> Wouldn't that also cause your DIC and radio to be permanently dimmed, as well as your parking lights to be permanently left on?


Wouldn't make a difference to me, I hardly ever look at my DIC or radio. *teehee




cecaa850 said:


> The most common reason I've seen is people running HID's. The low voltage or PWM modified signal tears the ballasts up. They work good with 12-14v, anything else, not so much. Don't know this particular poster's reason though.


Correct



XtremeRevolution said:


> Sounds like running a relay harness such as the one I made the writeup for (see my signature) would be the correct way to accomplish that. Not that HIDs in our factory housings are a good idea...


I Think a wiring harness has tried and unsuccessful. (i think)
I might try your write up, but its temporary.


----------



## cecaa850 (Apr 9, 2012)

There's no way to stop the PWM signal while at the same time allow the straight voltage for the low beams to pass. The delete will have to be on the control side somehow. There may be something you can do with the headlamp switch as it will turn them off when you toggle it. I need to keep digging.


----------



## cecaa850 (Apr 9, 2012)

Question. When you disable the DRL's with your headlamp switch, does it have to be done every time you start the vehicle?


----------



## XtremeRevolution (Jan 19, 2012)

Mick said:


> Wouldn't make a difference to me, I hardly ever look at my DIC or radio. *teehee
> 
> I Think a wiring harness has tried and unsuccessful. (i think)


I think it looks dumber to have your parking lights on in broad daylight all the time than it does to have DRL headlights on, which are required in some regions by law and is a safety feature. 

With regard to the harness, see below. 



cecaa850 said:


> There's no way to stop the PWM signal while at the same time allow the straight voltage for the low beams to pass. The delete will have to be on the control side somehow. There may be something you can do with the headlamp switch as it will turn them off when you toggle it. I need to keep digging.


How do you think I did it? Think about this for a second: 

I have a new wiring harness that uses two relays (one for high beams, one for low beams), and pulls power directly from the battery. The input signal is the H13 connector from the factory harness. 

What happens when you put a PWM signal through a relay? It spazzes out and you burn out the relay in short order. So, why do I not have this problem? Read my writuep and you'll see why.


----------



## cecaa850 (Apr 9, 2012)

You're not blocking the PWM signal, you're letting it pass. The capacitor is filling in the "off" pulses of the PWM signal. That's why it doesn't buzz any more. That's also why you're lights appear to have full low beam voltage. 12v from the PWM "on" cycle and 12v from the cap during the PWM "off" cycle.


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> You're not blocking the PWM signal, you're letting it pass. The capacitor is filling in the "off" pulses of the PWM signal. That's why it doesn't buzz any more. That's also why you're lights appear to have full low beam voltage. 12v from the PWM "on" cycle and 12v from the cap during the PWM "off" cycle.


Incorrect. Check again. The capacitor isn't placed in-line with the PWM signal. I tried that and ended up with no DRLs at all. 

Let me know if you give up and want me to explain how it works. Call it a bit of a a riddle.


----------



## cecaa850 (Apr 9, 2012)

I like riddles. OK, let me make a couple assumptions. First assumption, the relay buzzed because it was getting rapid on and off pulses from the DRL feed and not a constant 12v like it would have with low beams.


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> I like riddles. OK, let me make a couple assumptions. First assumption, the relay buzzed because it was getting rapid on and off pulses from the DRL feed and not a constant 12v like it would have with low beams.


Correct.


----------



## cecaa850 (Apr 9, 2012)

The cap must be wired like a PWM low pass filter which is NOT an in-line filter. I stand by my previous assertion as to it's operation. You may now enlighten me.


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> The cap must be wired like a PWM low pass filter which is NOT an in-line filter. I stand by my previous assertion as to it's operation. You may now enlighten me.


Cap is connected between low beam wire on the factory harness side going into the relay, and the low beam wire on the new harness coming from the relay and going into the bulb. 

When DRLs turn on, the PWM sends a pulsed signal, clicks relay on once. That first relay click functions as it normally would, opening the current flow from the battery through to the harness low beam wire. That then fills the cap. The cap being connected to the input wire then fills in the signal as it's being drawn by the relay. That allows constant power to the relay so it stays on so long as the PWM signal is received. Once the PWM signal shuts down, the cap is drained and the relay closes. 

I'm not an electrical engineer, but this is how I see it working.


----------



## cecaa850 (Apr 9, 2012)

Re-read my comment on the previous page. We're basically saying the same thing. I'm not an E.E. either, just inquisitive.

I have a possible work around in my head. Please critique as I don't have a car yet to play with. I may assume the vehicle acts in a certain manner when it doesn't.
When you toggle the headlight switch, it turns off the DRL's correct? I'm assuming the switch sends a ground to a specific terminal of the BCM and tells the BCM you want them shut off. The next part is an assumption. I'm assuming you have to do that every key cycle. In order for the car to automatically turn them off, you'd need a ground pulse to the BCM every time you start the car in order for them to be permanently disabled. What if you installed a relay and used the starter trigger wire on the control side to energize the relay. The relay would be wired to send a ground to the BCM on the load side. That way every time you start the car, the BCM would get the "turn off DRL" signal to the BCM. When the starter quits getting a signal, the BCM loses it's ground. No DRL's and all auto headlight functions still work.


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> Re-read my comment on the previous page. We're basically saying the same thing. I'm not an E.E. either, just inquisitive.
> 
> I have a possible work around in my head. Please critique as I don't have a car yet to play with. I may assume the vehicle acts in a certain manner when it doesn't.
> When you toggle the headlight switch, it turns off the DRL's correct? I'm assuming the switch sends a ground to a specific terminal of the BCM and tells the BCM you want them shut off. The next part is an assumption. I'm assuming you have to do that every key cycle. In order for the car to automatically turn them off, you'd need a ground pulse to the BCM every time you start the car in order for them to be permanently disabled. What if you installed a relay and used the starter trigger wire on the control side to energize the relay. The relay would be wired to send a ground to the BCM on the load side. That way every time you start the car, the BCM would get the "turn off DRL" signal to the BCM. When the starter quits getting a signal, the BCM loses it's ground. No DRL's and all auto headlight functions still work.


Well, what you said didn't have the bit about the battery providing power to the cap, which allowed the PWM signal to turn into a clean signal. Either way, the end result is full power low beams as DRLs. 

I don't believe what you're trying to do would work. The DRL lighting doesn't actually turn on (at least for my car, a manual trans), until the hand brake is released, so I don't think you would be able to wire that relay to the ignition switch.


----------



## cecaa850 (Apr 9, 2012)

Great point, I knew I was forgetting something. Mine will be a manual as well.


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> Great point, I knew I was forgetting something. Mine will be a manual as well.


Good call on the manual. I think the most straightforward way to do this is to wire in a relay with a capacitor, or just buy the wiring harness I listed in the writeup thread.


----------



## cecaa850 (Apr 9, 2012)

XtremeRevolution said:


> Good call on the manual. I think the most straightforward way to do this is to wire in a relay with a capacitor, or just buy the wiring harness I listed in the writeup thread.


That will work fine for me but I was trying to help the original poster with his problem which was disabling DRL's. As of yet, I've struck out, but I haven't given up.


----------



## Chevyderek72 (May 16, 2011)

XtremeRevolution said:


> I'm still trying to find out, what exactly was the purpose of disabling DRLs?


Well I am running hids so I need the full voltage at all times.

Sent from my DROID X2 using AutoGuide.com App


----------



## cecaa850 (Apr 9, 2012)

Chevyderek72 said:


> Well I am running hids so I need the full voltage at all times.
> 
> Sent from my DROID X2 using AutoGuide.com App


Xtreme's mod will work for you but your low beams will be on as DRL's AND low beams. You won't be able to shut them off.


----------



## XtremeRevolution (Jan 19, 2012)

cecaa850 said:


> Xtreme's mod will work for you but your low beams will be on as DRL's AND low beams. You won't be able to shut them off.


Well, you can still shut them off manually every time the car starts, lol. The only difference now is that the DRLs are the same power as the low beams.


----------



## Tallboy (Jul 5, 2011)

The easiest way to disable DRLs [and auto headlamps] is to take the headlamp switch apart and cut the spring. Once that's done, you can rotate the switch to "off", and it will stay there. Ta-da...manual headlamp switch.


----------



## Cruzer_1 (Dec 17, 2011)

and how does one go about doing this? as i live in canada i cannot turn the DRLs off at all.... do you know if cutting this spring would fix this or is it something in the computer?


----------



## sciphi (Aug 26, 2011)

Mick said:


> I Think a wiring harness has tried and unsuccessful. (i think)
> I might try your write up, but its temporary.


I was the pioneer of the lighting harness on the Cruze, and mine's working just fine since I installed it in late November 2011. It did take some fine-tuning to get just right, and I didn't exactly have a lot of free time to get it done at that time thanks to work being nuts. I made my harness to be permanent, and it's going to stay in the car as long as I own it. 

For the DRL's, I simply rigged the low beams to run at full power all the time via a capacitor smoothing the PWM signal for the DRL. I wanted to keep the DRL functionality since my car's black, and my area is up there with Seattle for highest number of gray, overcast days in the US. Also, many new cars have run into issues with DRL's destroying bulbs since they don't get enough voltage to let the halogen cycle operate. The filament ends up coating the inside of the bulb's glass since it does not get hot enough to burn off those deposits. This sidesteps that issue, but does bring up the issue of bulb life. H13 low beams have a pretty good bulb life as it is, so I'm not too concerned. Oh well, I'll find out one of these days!

I viewed the DRL operating at full low-beam power as a good thing for my driving and my area. The more warning the clueless yokels around me have that my car is approaching, the better! Having the DRL on has saved my rear end a whole bunch, as people who would have pulled out in front of me without looking see the DRL and slam on the brakes. They're also less likely to come at me head-on in a short passing zone when they see the lit-up car in the distance approaching.


----------



## Skilz10179 (Mar 22, 2011)

Rather than locking this thread i deleted pointless arguments that became more of a personal level than anything beneficial to the forum members here. 

Enough is enough... You may continue *on topic.*


----------



## Tallboy (Jul 5, 2011)

Cruzer_1 said:


> and how does one go about doing this? as i live in canada i cannot turn the DRLs off at all.... do you know if cutting this spring would fix this or is it something in the computer?


I'm unsure. If your DRLs come on or are still on when you shift into gear [after turning the switch to "off"] this mod will NOT work for you. I just don't like auto headlamps or DRLs, so I cut the spring. Did it on my Camaro too.


----------



## sciphi (Aug 26, 2011)

Cruzer_1 said:


> and how does one go about doing this? as i live in canada i cannot turn the DRLs off at all.... do you know if cutting this spring would fix this or is it something in the computer?





Tallboy said:


> I'm unsure. If your DRLs come on or are still on when you shift into gear [after turning the switch to "off"] this mod will NOT work for you. I just don't like auto headlamps or DRLs, so I cut the spring. Did it on my Camaro too.


That's one way to fix the DRL's! It's your car, do as you wish. I purposely kept them with my lighting upgrade. Still, enjoy the mod!


----------

