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

Dbeto54 · August 4, 2016

Alright guys I got my plugs this morning and repined only the drivers side so far. What I have found is the everything works like it should with the headlight switch however the DRL does not cut off when the truck is in gear and the turn signal is applied. Another thing is the headlight works fine until I start the truck then after a few secs it will flicker then cutoff. I haven't finished testing but this is what I have found so far. Any suggestions while I have it apart?

I know why they stop working while truck is on, you need to add some capacitator. I wasnt sure if the SLT came with hid or regular bulbs. Dont know why but while truck is running it gets pulsating current and causes the headlight to cutoff but if you put this capacitators it will make the current flow evenly without pulsating. It goes on pin 1. Ground Black-Black and 2. Low beam Yellow-Red

Any local HID supplier should have them in stock

Edited August 5, 2016 by Dbeto54

Dbeto54 · August 4, 2016

I guess the turn signal function is control through the bcm

Edited August 4, 2016 by Dbeto54

abominable z71 · August 4, 2016

Alright guys I got my plugs this morning and repined only the drivers side so far. What I have found is the everything works like it should with the headlight switch however the DRL does not cut off when the truck is in gear and the turn signal is applied. Another thing is the headlight works fine until I start the truck then after a few secs it will flicker then cutoff. I haven't finished testing but this is what I have found so far. Any suggestions while I have it apart?

Perhaps this will help

And this to complete the Pepsi challenge

2015 headlights.pdf

2016 headlights.pdf

2015 headlights.pdf

2016 headlights.pdf

zmnypit · August 5, 2016

I know why they stop working while truck is on, you need to add some capacitator. I wasnt sure if the SLT came with hid or regular bulbs. Dont know why but while truck is running it gets pulsating current and causes the headlight to cutoff but if you put this capacitators it will make the current flow evenly without pulsating. It goes on pin 1. Ground Black-Black and 2. Low beam Yellow-Red

Any local HID supplier should have them in stock

I've got some capacitor's from my buddies Silverado hid kit I installed. I'll try one out tomorrow. Also still have the morimoto switch back drivers I will be trying with the repin. Edited August 5, 2016 by zmnypit

Arth · August 5, 2016

I've got some capacitor's from my buddies Silverado hid kit I installed. I'll try one out tomorrow. Also still have the morimoto switch back drivers I will be trying with the repin.

You have it narrowed down to simple stuff now. A capacitor link will clean the signal and a switch back setup will give us the desired effect with the DRL.

abominable z71 · August 5, 2016

Pulsing current shouldn't happen on the slt models because they have a separate drl the truck only uses pwm on the sle low beam for the daytime running lights

Edited August 5, 2016 by abominable z71

abominable z71 · August 5, 2016

Wrong thread

Edited August 5, 2016 by abominable z71

Arth · August 5, 2016

You would think that but I used to own a 2013+ Ram 1500. The Ram trucks don't even have DRL here in the states unless activated by the dealer.

That being said the Ram trucks use PWM and require the use of a capacitor link or error eliminators to run HID's and such. So it's not that big of a surprise that the SLT Sierra uses it as well. Can't really explain why except it's how they designed the PCM to run the truck.

Pulsing current shouldn't happen on the slt models because they have a separate drl the truck only uses pwm on the sle low beam for the daytime running lights

fishlessam · August 5, 2016

Alright guys I got my plugs this morning and repined only the drivers side so far. What I have found is the everything works like it should with the headlight switch however the DRL does not cut off when the truck is in gear and the turn signal is applied. Another thing is the headlight works fine until I start the truck then after a few secs it will flicker then cutoff. I haven't finished testing but this is what I have found so far. Any suggestions while I have it apart?

You need LED canbus decoders not HID,same thing happened in my conversion.

ricker6869 · August 5, 2016

You need LED canbus decoders not HID,same thing happened in my conversion.

Fishlessam, can you give us a little more detail on your conversion?

Thanks

Dbeto54 · August 5, 2016

You need LED canbus decoders not HID,same thing happened in my conversion.

Im using an HID decoder because thats what I had handy and lights are working great, dont know for how long it will work than.

Edited August 5, 2016 by Dbeto54

abominable z71 · August 5, 2016

You would think that but I used to own a 2013+ Ram 1500. The Ram trucks don't even have DRL here in the states unless activated by the dealer.

That being said the Ram trucks use PWM and require the use of a capacitor link or error eliminators to run HID's and such. So it's not that big of a surprise that the SLT Sierra uses it as well. Can't really explain why except it's how they designed the PCM to run the truck.

i converted my lights over to HID, Built my own harness and installed Denso ballasts out of a lexus, no cap's were required. Zmny's issue is that the BCM is looking for a different resistance on that circuit because LED's function at a much lower voltage than what the BCM is looking for from the original halogens because the bulb itself functions as a resistor in the circuit where the LED is a diode. With a cap in the circuit once the plates are charged, in theory unless the capacitor breaks down the circuit should be open so if current is actually flowing through that circuit and providing power to the light the capacitor has broken down and the dielectric between the plates is function as a resistor. It's been 12 years since I took circuit's in college but if I recall correctly that's how a capacitor functions in a dc circuit. What you actually want is a resistor in the head light circuit to mimic the halogen bulb which is bascially the canbus corrector fishless is talking about.

fishlessam · August 6, 2016

Fishlessam, can you give us a little more detail on your conversion?

Thanks

My truck is a 2014 sierra denali white diamond ,the stock headlights/tail lights suck real bad just like others have complained,so I decided to change them to the 2016 denali lights.I bought the pair of led headlights and forward harness from GM and did the install myself(automotive tech),the lights turned on with the key in the run position but as soon as I started the truck the led headlights turned off,i was disappointed.I drove like that for a week trying to figure out the cause,what I noticed was when the voltage dropped below 12volts, the leds worked perfectly,tried to do a reflash at the dealer but no luck.Did some googling about led headlights and they all had one thing in common,LED CAN-BUS decoders.So I installed a pair and bingo,everything is fine except that in the daytime the DRL dosent turn off when I signal but that dosent bother me.I also changed the rears to 2016 LED tail lights.

zmnypit · August 8, 2016

Didn't get to test the turn signals this weekend as I was busy and needed my truck so I had to put it back together. However, I installed some capacitors between the low beam/ground wire before reassembly and the headlights function just fine with the truck running. I tested them Fri & Sat night and not a single issue so far. So it appears for those willing with an SLT only a repin & capacitor is needed for the lights to work like the 14-15 slt lights. Now if I can only get those DRL's to go off when turn signal is applied.

Edited August 8, 2016 by zmnypit

ricker6869 · August 8, 2016

Didn't get tot test the turn signals this weekend as I was busy and needed my truck so I had to put it back together. However, I installed some capacitors between the low beam/ground wire before reassembly and the headlights function just fine with the truck running. I tested them Fri & Sat night and not a single issue so far. So it appears for those willing with an SLT only a repin & capacitor is needed for the lights to work like the 14-15 slt lights. Now if I can only get those DRL's to go off when turn signal is applied.

zm,

Could this be made to work on an SLE model? Do the SLT harnesses have additional wiring for the LED DRL,s?

Dbeto's silverado conversion basically went NON-LED headlights to 2016 LED DRL headlights with only repin correct?