GM90

Been out of the country for a couple years but finally back. While browsing Reddit I saw that someone is actually making those amber DRLs now, looks like it is called Venom. I remember getting a bunch of messages asking how I made mine, and I promised a few people I would explain, but I never got the chance to reply. Sorry about that. I'd loved to have manufactured this and made a tiny bit of money from it but i didn't have the resources. Anyways, now you do not need to DIY because there is a proper harness available. Cheers. https://venomtrucks.com/product/gmc-sierra-amber-running-lights/

I won’t be making these myself, but I’ll share the instructions here. The most challenging part was designing the PCB, which I’ve already completed through a lot of trial and error. I’ll upload the PCB files so you guys can get them printed at JLCPCB.com—this is the service I used. Once you have the control board, all you need to do is create four pigtail harnesses (two for each side) and place the board in a waterproof/weatherproof enclosure. I’ll also look up the part numbers for the connectors and pins. The installation is simple: unplug the harness from the headlight housing, connect it to one side of the PCB, and then plug the pigtail from the other side of the PCB into the headlight. If you’d like the option to switch between amber and white DRLs, you can run two wires from the PCB into the cab and install a two-position switch. Alternatively, if you don’t want to run wires into the cab, you can place a small jumper on the PCB itself, allowing you to have either white or amber LEDs. (Can't switch colors on the go) I’ll try to make time for a more detailed write-up with pictures. I’ll need to sift through some old emails since it’s been a while. The lights have been working great and look fantastic. I haven’t had any issues with them. As a courtesy to other drivers, I switch to the white DRLs at night because they automatically dim with the light sensor, while the amber ones are super bright.

In the first picture, You can see how the mudflap looks WITHOUT the metal bracket, that used to be there. The aqua color indicates where I used the screws to secure the mudflap. I also trimmed the wheel liner, indicated by the red line. This is trial and error. Online you'll see some people just chop the plastic mudflap in half. I wanted to take out as little as possible. So after a few tries, this is what I ended up with. You can see in the first picture how it looks, it still looks like a mudflap and the bottom splash guard is still there. For the front, same thing. The plastic piece that I cut, is only used to hold the wheel liner in place. Again, online people just cut the whole thing is half, I just cut what needed to be cut. I used one original mounting area for the screw and then used a self tapping screw at the other mark. I did this a process a few times that day. I would modify and then put the tire on. I would check around and see what's rubbing when its on the ground. I also took it for a drive few times and make sure there were no rubs when turning or going over bumps when the suspension is compressed. Also I used this Milwaukee Oscillating tool

I think on the 19-21 Sierras the DRL and turn signals reside in separate places in the headlight. They're not similar to the new Sierras where the DRL and turn signals are in the same place. The new Yukons and 24+ Sierra HDs on the other hand would probably work similar to the 22+ Sierra 1500s

I guess ya, if there's enough interest. I can manually make these, bu they are time consuming and parts are expensive. especially the PCBs. They are cheaper to make in larger quantities, and instead of locally, they will be 1/4 of the cost if they are made in China. I'm making two of these for my buddies but they're eating up the cost and labour.

I saw that these trucks had full amber lights and wanted to use those as DRLs. I looked online and found only few options: One was to bake the headlights in the oven and take them apart and replace the white DRL Led strip with yellow one. This is too much work and chances of getting it right are pretty slim. For me at least. Not to mention no more warranty on headlights. Other option was to replace it with aftermarket headlights, but those are all junk and look very cheap with very dim dotted DRL LEDs. I opted to design my own little circuit board that controls the function of these DRLs. The circuit board I made is very small and compact, about 4x4in. The weatherproof case is about 6x6in. And for it to work you just unplug the harness from the headlight and plug this in between and you get amber DRLs which you can change with a switch in the cab. It was a lot of trial and error and spent a good amount of money on versions of different PCBs that had to be printed and after a few revisions I got it working. And the OEM harness plugs were hard to find initially but lucked out and found em online. I made it plug and play, because I didn't want to hack or modify any harnesses or headlights and maintain the warranty on those items. GM is notorious for voiding warranty for stupid ******. This way I can just pop these modules out before I bring it for a service. What the PCB does is, when its on, the DRL signal to white LED stops and in its place the amber LEDs light up. The hard part with designing the circuit was retaining the turn signal and hazard lights functionality along with the amber DRLs. And making it all work with the turn signal feedback loop. When the PCB is off, then it acts as a pass through, like its not even there. Then everything works in factory mode as GM intended.

TIRES - 305/55R22 (35.5inch tall by 12 inch wide) - Actually 35.9inchs with measuring tape - Nitto Recon Grappler Tires WHEELS - GMC 22 Inch Aluminum 5-Split-Spoke Wheel - Part# 84799395 I added 10mm Bora aluminum spacers to be able to fit 12inch wide tires without rubbing. Also had to trim the front mudflap brackets and wheel well liners, to eliminate the rubbing at turns. I didn't want to add any lift because AT4s already come with factory 2inch lift and I like the filled out wheel wells. Don't like the look of empty wheel wells.

It was really smoky in those yellowish pictures.

I took some pictures of my truck few days ago, thought I'd share. Tires are on 22inch rims and they're around 35.8inchs when measured using a measuring tape. Borla S-type exhaust with dual exhaust tips on each side.

Wow that is a complicated process. Do the 2019 not have the amber and whites like the 2022s; white for DRL and amber for turn signals? I'm hoping to find a solution where I can return it to factory quicky. Either by removing the jumper harness or changing the settings in ECM. With Fords, you can increase or decrease the brightness of the DRLs using an OBD connector and a laptop with Forscan software. I was hoping GM would have a similar method. I still haven't heard from anybody at GM to tell me if its possible to change it via the ECM or not. My other option was to insert a custom harness between the factory harness and the headlight assembly. And If I could figure out the wiring information, then I could simply make the Amber as DRLs and keep them as turn signals. I don't know how easy this would be, as I haven't even popped open the hood to see if its feasible or not. Edit: I think the factory ambers are plenty bright as they need to be clearly visible in daytime for the turn signal/hazard function.

I asked this in "Ask a GM tech" forum back in December but got no responses. I want to replace the white DRLs with the Ambers from the turn signals. I was wondering if GM could enable this option electronically by changing some parameters with their computer. If not, then I can make a pigtail harness that goes in between the factory harness to the headlight assemblies. I would need a wiring schematic showing the wires going to the headlights and also the male and female connectors that are used. Wondering if someone can help me out. Thanks.

Can someone provide me with the wiring information for the DRLs and the turn signals? I can try to make a custom harness where I can have the ambers be the turn signals and the DRLs. Thanks.

just bumping this.

The Ford software? You can get it at Forscan.org

There is a software called Forscan for Fords. In the past I have used it to change the brightness of DRLs on my F150 and enable a mod where fog lights stay on when high beams are activated. I was wondering if a similar software exists for GM. or if need be, I can take it to the dealer and have them change the configuration on the DRLs, if its even possible to do with software.