2016 SLT lights in 14/15 SLT/All Terrain almost done

Payton34 · April 12, 2017

Thats not whats going on, GM uses a PMW on all there lighting, if you put it on a scope you will see this ---^---^---^----^----^ from 14V UP TO 18V, that is why you need a cap, but use ones with a 4700 MF ant 25V and up.

And we do have the same harness that you guys are sealing, right now we only have them marked as for the HD but they will work.

What is this cap? is it the headlight housing of part of the harness? Also wouldn't this issue be occuring on both side of the truck if there was irregular voltage.

Edited April 12, 2017 by Payton34

2SSRS · April 12, 2017

That ground wire is for the entire head assy. If you had an issue on that wire you would have problems on all lights, Park/Turn/DRL/Low beam/High beam. inside of the head assy is a junction where all the grounds come together and exit the head light via pin 1. Pin is connect to the original delphi 280 connector by the adapter harness you got from Vann. From the original connector on pin a the ground wire runs down to the frame location. it sounds like you have a problem with power jumping across from the turn signal to the DRL wire. They share a wiring harness from the fuse block down to the x110 connector. Other wise the DRL and turn signal are different harnesses out of the BCM to fuse block. I have attached a wiring diagram I made while researching and building my harnesses. Not sure if it'll help much.

HEADLIGHT WIRE DIAGRAM LEFT.pdf

Who did the PDF? its not right, the resister does not go on only the power wire it goes to ground on the other side.

Edited April 12, 2017 by 2SSRS

2SSRS · April 12, 2017

What is this cap? is it the headlight housing of part of the harness? Also wouldn't this issue be occuring on both side of the truck if there was irregular voltage.

I know, i went to school a long time ago, but when i did go to class, i went to shop class and the word for Capacitor was and i think still is Cap.

abominable z71 · April 12, 2017

On the 14-15 its pin E and H. Both are just Park lamp supple voltage. Like I mentioned tho leaving it out makes no difference as long as one of them is used. I tested both ways on my repin of my truck and nothing changed. I just add them mostly out of habit and you never know what kind of scenario you may run across if I left it out. Actually had a guy using that wire for something to do with a snowplow.

E and H are junctioned down stream of the X50A connector. Essentially the same wire. So you connect one of the park lamp signals into the run crank on pin 6?

abominable z71 · April 12, 2017

Who did the PDF? its not right, the resister does not go on only the power wire it goes to ground on the other side.

I did, it doesn't matter if the resistor goes to ground or is cut in parallel like shown.

zmnypit · April 13, 2017

Thats not whats going on, GM uses a PMW on all there lighting, if you put it on a scope you will see this ---^---^---^----^----^ from 14V UP TO 18V, that is why you need a cap, but use ones with a 4700 MF ant 25V and up.

And we do have the same harness that you guys are sealing, right now we only have them marked as for the HD but they will work.

The DRL will pulse like that? Or you talking about the LED low beam. I know the low beams need the cap but his DRL is flickering not headlamp.

Payton34 · April 13, 2017

I am going to plug the stock headlamp back in to see if the drl flickers. I am positive I never saw it flicker before I removed them but I am actually hoping it does because then the dealer will have to fix whatever is wrong under warranty. I tested the ground and it is working so it does seem the power between the drl and turn signal are crossing some how but only if the truck is cold. If I turn on the parking lamps or headlights when the truck is cold the drl doesn't flicker with turn signal. The hard part is testing all the possibilities I have a limited window to try things. Once truck is warmed up everything is ok and I have to wait for it to cool down a few hours.

Payton34 · April 13, 2017

Plugged stock headlight in and the drl doesn't flicker with the turn signal so I have ruled out the truck wiring, and the driver side Led headlight is ok when plugged into passenger side so the housing are not the problem

abominable z71 · April 13, 2017

Plugged stock headlight in and the drl doesn't flicker with the turn signal so I have ruled out the truck wiring, and the driver side Led headlight is ok when plugged into passenger side so the housing are not the problem

Just for kicks replace the 20A fuse in location number 6 on the left side fuse block. This fuse block is behind a panel on the side of the dash on the drivers side.

2SSRS · April 13, 2017

The DRL will pulse like that? Or you talking about the LED low beam. I know the low beams need the cap but his DRL is flickering not headlamp.

Ok here goes, first off you all know the way you control LED'S right? there turned on and off 100 time a second, if you have a movie camera on your cell record when your DRLs are on, then play back and watch your lights flicker, now there is a tolerances on all DC power so what you may have is a car harness that is off more then the outer side, and yes there is a volt spike on the turn signal too.send him a harness that has a cap on that side too.

Payton34 · April 14, 2017

Just for kicks replace the 20A fuse in location number 6 on the left side fuse block. This fuse block is behind a panel on the side of the dash on the drivers side.

I tried the number 6 and all other fuses labeled BCM but didn't change anything.

Horacio · April 15, 2017

Guess what?

I just checked mine and my driver side flickers too.

First thing in the am, pull out of the garage, allow the auto Headlights to shut off and DRL to come on. Put the truck in Drive, apply emergency brake, turn on left signal, got out and checked and low and behold, I got LED flicker.

Payton34 · April 15, 2017

I thought there was something wrong with my truck since no one else had this issue but I guess the harness needs a capacitor for the drl too. I wonder why some trucks don't have this issue. Wonder if it depends on options or the engine size.