# PWM headlight control for cars with projector lights?



## WillL84 (Aug 5, 2019)

Hey guys, I'm about to hit order on a set of GTR Ultra 2 bulbs for my Cruze. In chatting with the Headlight Revolution guys they said I'd need a PWM interface module as well. But the LT and Premier Cruze's that come with projector's have dedicated LED DRL strips and don't PWM modulate the low beam to act as a DRL as far as I know. I could just order them and return them and be out return shipping or I could not order them and then order them later if I find I needed them but then it's extra shipping lol.

Can anyone confirm? I know the HR guys said I'd need them but they're also more adept to trucks as they don't list anything for cars on their site. I know some cars do use the low beam (or even high beam in a lot of cars these days) in PWM mode at like half brightness as a DRL. Thanks!


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## WillL84 (Aug 5, 2019)

Well I pulled the trigger and pre-ordered the GTR Ultra 2 bulbs and the PWM adapter and got a free set of LED signal bulbs from Headlight Revolution on their Black Friday sale. It says estimated release date is 12/5 so hopefully in a couple weeks I'll have them and we'll see whether or not the PWM boxes are needed.


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## Chad20101 (Jul 23, 2019)

You won’t need that since the LED are the drls an not the actual headlights.


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## WillL84 (Aug 5, 2019)

From what I've seen though Chevy may still use PWM control for the headlights. They apparently do in the Silverado's starting from like 2012/2013 even though some have LED DRL's as well. I got it coming either way though, I can just send it back if I don't end up needing it.


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## Chad20101 (Jul 23, 2019)

Okay after doing some digging through the this form the headlights are controlled the BCM , Some people have mention not needing anything when upgrade to LED or HID headlights.


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## WillL84 (Aug 5, 2019)

Chad20101 said:


> Okay after doing some digging through the this form the headlights are controlled the BCM , Some people have mention not needing anything when upgrade to LED or HID headlights.


Diode Dynamics SL1 bulbs don't need them but they apparently have them built in. DD confirmed to me that they did not need them and they were plug and play. Like I said though I can send them back if I end up not needing them.


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## Chad20101 (Jul 23, 2019)

I thought about going that route because the factory headlights suck , I’ve heard about the 9011 bulb mod but it’s hard to find true HIR bulbs.


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## Snipesy (Dec 7, 2015)

Internally it likely still uses the PWM controller just at 100%. It’s possible it may be set to something like 95% in which case you would still see a pulse.

But even 95% shouldn’t really effect it any.


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