LED DRL Conversion

[ado]

I have read many threads on here about deleting/relocating DRLs on the 2015-2019 HD Chevrolet trucks. I wasn't ever that concerned with it until I decided to upgrade my headlights. I bought the Morimoto XB headlights (that have not arrived yet) that have the separate LED tubes in them as well as LED headlights. This would also come in handy for HID upgrades as well (not burning them during the day). I wanted the LED tubes to act like the factory DRLS, not the lowbeams. As you may know, GM uses PWM (pulse width modulation) over 1 wire to differentiate between DRL and full low beam. I also wanted to keep all factory automatic headlight operation, just activating LED running lights instead of lowbeams when in gear.  This excluded the pin swap and the switch mod because I wanted the automatic function to remain intact. To the drawing board I went!

 

What I came up with was a harness that will T into the factory harness between the headlight and factory plugs. All wires are passed through except the low beam. The low beam input is redirected to a circuit I created to filter the PWM and only activate a relay when full lowbeam signal is sent. After the circuit design and testing, I got some PCBs made and put it all together.  I then tapped the trailer brake running light fuse to power the circuit so it has power after the truck is shut off until the lights turn off which helps with all of the factory light operation. I have installed everything and it works as expected, I have no DRLS currently with everything else functioning like the factory automatic settings would. I'm just waiting for my headlights to come in so I can get them installed and get the LED tubes hooked into the DRL signal! Here are a few pics of the setup.

 

Harness

 

 

Circuit - I'm going to fill the box with epoxy once completely done for weatherproofing

 

 

Pass Side Tap

 

 

Cross Harness

 

 

Driver Side Tap

 

 

Relay

 

 

Circuit in Box

 

 

 

 

I will get some updated pictures of the DRL operation if my headlights ever arrive! I have been waiting since the beginning of April for them when they were on pre-order. 

Edited July 1, 2020 by ado

[Chad Walker]

Sweet.  So you will be manufacturing and selling these?  By the way, that isn't a question.  

[ado]

That may be a challenge. I wouldn't be able to manufacture them myself on a large scale, but depending on quantities I probably could. I just got an update on the Morimoto XB headlights and they are now saying December 1st as a release date. 

[ado]

I finally got the XB headlights and what a difference. The LED's act as the DRL now when the truck is in gear. All auto functions work just like factory. No low beams for DRL. 

 

It's dirty...but here are a few pictures. More to come...

 

 

All lights on...

 

 

The pictures don't show the pure white of the lights.

[Chad Walker]

Excellent.  That is the one thing I miss about my Ford.  I could change the DRLs with software and an OBD2 connector.  We need something similar for GM.

[chevyzr1]

On 2/8/2021 at 12:24 PM, ado said:

I finally got the XB headlights and what a difference. The LED's act as the DRL now when the truck is in gear. All auto functions work just like factory. No low beams for DRL. 

 

It's dirty...but here are a few pictures. More to come...

 

 

All lights on...

 

 

The pictures don't show the pure white of the lights.

Did you have to wire them for the drl's to be on the leds or do they come that way ? I also ordered these for my 2019 and I'm still waiting on them. One thing I'm a little disappointed with after seeing your pictures is it looks like the side marker has an amber lens yet on the trs website they make it look like it's a clear lens with an amber bulb. Looks a million times better than factory headlights !!!! How is the performance? I have the d2s projectors with dense bulbs and computers and I will say I think they'll be hard to beat as far as output. Thanks again for sharing they look great !

[ado]

These trucks use 1 wire to the low beams from the factory for the DRL and low beam. The circuit I created and built splits that signal into DRL and low beam for two different bulbs. In this case the DRL portion is wired to the LED strips in the morimoto lights that activate when in gear and the low beams only come on when lights are needed. They do look much better! So far so good on performance, just need to get them adjusted when I can find the time after dark. 

[ado]

Well I finally got some more pictures up.

 

Daytime running lights, only when in gear. They are brightest here.

 

 

Running lights on. Dims the LED DRL

 

 

Headlights on

 

 

I set the turn signals to scroll, so as one side scrolls, the other stays white.

 

Here is a short video on that. It sped up a little when converting it, I'm not sure why. It does not flash that fast in real time.

 

 

Overall they are working like expected and a big upgrade in my opinion over factory.

 

 

[RaceCitySilv]

@adoThis setup is exactly what I am trying to achieve. Can you give any more insite into the harness you made? I would like to try making my own or possibly buy one from you if your selling???

[DBeau]

I second that, I would like to get on that list if your willing to sell the kit.