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.

Is it possible to change the DRLs from white to amber? 2022 refreshed Sierra has white always on DRLs and the DRLs turn amber for the turn signals. Can the white DRLs be turned off and amber ones turned on to act as DRLs? Would this be a physical mod? or a software mod? Thanks

That's why GM is number 2 to Ford. I'm not loyal to any brand, but warranty work on my F150 was always a breeze. In fact I remember one time I was over the basic warranty by 5000km and needed the ECU replaced. ECU is free under warranty and $800 out of warranty. So, even though I was over the warranty mileage by 5000km, Ford dealer still replaced the ECU free of charge. I took my 1500 in today for some warranty work and didn't even get a loaner, which is usually covered in the warranty.

I run Nitto Recon Grapplers 305-55R22, they're way quieter than Duratracs and good in rain. Mine are 35.2inch tires but im sure they come in the size you're looking for. I also run Nitto Exo Grapplers for the winter, because they're stud-able and better in ice and snow. Here is what I posted in another thread:

No I stopped looking into it when GM dealers told me that I might void my powertrain warranty because I have changed the wheel size or use a module for the speedo calibration. I spoke to few dealers who said, GM has denied powertrain warrant claim for vehicles that had their tire size different from what OEM options are. Some say the speed calibration module leaves an imprint the vehicle ECU that tells GM that the vehicle was using the speedo calibration module. I guess it depends on the dealership and the claim manager but I can see GM using any excuse necessary to weasel out of a claim, especially its gonna cost them a lot of money. I will wait and see what options become available and if GM causes issues with them. Off topic: is there a software similar to ForScan (for Ford) for GM vehicles? I have used ForScan to change a lot of options on my F150, like Bambi mode, that allows Highbeam and Fog lights to be on at the same time and increase the brightness of DRLs etc... lots of ECU modification with ForScan. I was hoping a similar product existed for GM.

Yea that's what I figured. The dealership said I'd be looking at 2-4 months for the grille. He said if it was 4-5 weeks it would show in the inventory. I called most of the GM dealers in Canada, and the ones who had this grille on hand, they were holding it for the body shops. I tried to see if I could get the elevation or vader chrome grille off the Denali Ultimate lol. Same issue. It was a fully grown deer, and I was doing about 110km/h (~65mph). It was about one second when I applied the brakes and hit the deer. So I had slowed down to maybe 60kmph. And I hit its ass end, as it was mostly off the road. But it still managed to get airborne and land in the ditch.

I slammed on the brakes and grill took majority of the impact. I saw the deer go up 10-12ft and land in the ditch. I was expecting my front end to be smashed as well. Guess I got lucky and thank god the air bags didn't go off, as that would've cost more.

I don't know if I will, as I switch between both Ford and GM. I usually don't mess with the wiper setting too much either as I leave the setting on Auto. And if I need a wipe in between, then I just use the quick wipe button. But on this I always have to move the wiper switch from whichever setting its at, all the way to the bottom and twist it for a quick wipe then rotate the switch back all the way back to where it was. Seems pretty stupid in my opinion. I'm new to GM, so maybe the GM customers are already used to it. But I would love to be able to remap the button.

These tires are way quieter than than the duratracs the truck comes with.

Met a guy at the dealership today, who was buying a similar truck as mine. He looked at my set up and wanted to replicate it on his AT4. He priced out everything at the dealer and seems the costs have gone up. He got a quote that was almost $1000 higher than what I spent for the exact same parts.

Went to the dealership expecting to grab a new grille for $400-$500. Instead found out that the grille is $1800CAD and there is no stock or ETA from the manufacturer as it is on back order.