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

zmnypit · April 11, 2017

Alright we have a strange on here. A few pages back Payton34 mentioned his drivers side DRL would flicker while using the turn signal. I got in contact with him and after looking around found a lose ground wire on my harness. I sent him a new on that day and he installed it and the DRL still flickers when the turn signal is applied but seems to function properly once the truck is warmed up or the parking lights are on. So here we are 2 different headlights, 3 harnesses and the same issue. The last adapter I sent I installed on my buddies truck before sending just to verify no issues so I know we know it works. This seems to be a truck voltage/ground issue. Anyone have any clue as to what would cause this? He's already checked the grounds behind the front bumper and they are fine. The passenger side works as advertised so Im at a loss here. Also including his thread below:

http://www.gm-trucks.com/forums/topic/199987-led-drl-flickers-when-using-turn-signal/

Edit: Another thing to note. It seems to be intermittent. This morning for example it never flickered it all. This afternoon or at lunch it may start again.

Edited April 11, 2017 by zmnypit

BringTheRain403 · April 11, 2017

Is there a ground somewhere else along the line that could be affecting it? Like by the fuse box or the BCM?

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zmnypit · April 11, 2017

Is there a ground somewhere else along the line that could be affecting it? Like by the fuse box or the BCM?

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Behind the front bumper on the frame. I had him check those and all is well.

BringTheRain403 · April 11, 2017

How about the ground on the battery or the one on the block? If it's fine once the truck is on then it's gotta be heat related. Maybe the big ground on the block is loose and when the truck heats up and everything expands it tightens things up?

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abominable z71 · April 11, 2017

Alright we have a strange on here. A few pages back Payton34 mentioned his drivers side DRL would flicker while using the turn signal. I got in contact with him and after looking around found a lose ground wire on my harness. I sent him a new on that day and he installed it and the DRL still flickers when the turn signal is applied but seems to function properly once the truck is warmed up or the parking lights are on. So here we are 2 different headlights, 3 harnesses and the same issue. The last adapter I sent I installed on my buddies truck before sending just to verify no issues so I know we know it works. This seems to be a truck voltage/ground issue. Anyone have any clue as to what would cause this? He's already checked the grounds behind the front bumper and they are fine. The passenger side works as advertised so Im at a loss here. Also including his thread below:

http://www.gm-trucks.com/forums/topic/199987-led-drl-flickers-when-using-turn-signal/

Edit: Another thing to note. It seems to be intermittent. This morning for example it never flickered it all. This afternoon or at lunch it may start again.

Sounds like it may be an issue with the controller module. Gm gives them 2 different part numbers K166L and K166R. These are the heat sink looking things on the back of the light. Here's one thing I discovered while installing mine expanding on what Vann found while testing his. Without a minimum of a 4700 uF capacitor on the low beam the light functioned fine while the truck was off and being powered strictly by the 12v DC battery, once the truck was started the light would flicker after about 5 seconds then come back on after about a minute and work fine from that point until the truck was shut off and restarted. The problem is with the alternator making ac current and rectifying back to DC, the power just isn't clean enough until the truck has run for a bit and the cap smooths it out to prevent this. While I never saw an issue with the DRL's this might be the case. Perhaps putting a 4700 uF cap on the DRL would prevent this it might not need to be this large for the DRL maybe a 2200 would work but a 4700 should do it? Although my money would be on the K166L controller as the issue. you can find them on ebay.

Edited April 11, 2017 by abominable z71

zmnypit · April 11, 2017

Sounds like it may be an issue with the controller module. Gm gives them 2 different part numbers K166L and K166R. These are the heat sink looking things on the back of the light. Here's one thing I discovered while installing mine expanding on what Vann found while testing his. Without a minimum of a 4700 uF capacitor on the low beam the light functioned fine while the truck was off and being powered strictly by the 12v DC battery, once the truck was started the light would flicker after about 5 seconds then come back on after about a minute and work fine from that point until the truck was shut off and restarted. The problem is with the alternator making ac current and rectifying back to DC, the power just isn't clean enough until the truck has run for a bit and the cap smooths it out to prevent this. While I never saw an issue with the DRL's this might be the case. Perhaps putting a 4700 uF cap on the DRL would prevent this it might not need to be this large for the DRL maybe a 2200 would work but a 4700 should do it? Although my money would be on the K166L controller as the issue. you can find them on ebay.

He's already swapped the lights with new ones as we thought the light itself may be bad. Thats me, with all the sets sent out not one DRL flicker. Even his passenger side doesn't flicker. I has to be something in the wiring I would assume.

abominable z71 · April 11, 2017

He's already swapped the lights with new ones as we thought the light itself may be bad. Thats me, with all the sets sent out not one DRL flicker. Even his passenger side doesn't flicker. I has to be something in the wiring I would assume.

If i'm understanding you correctly He swapped the entire head light assembly with another one and it still has a flickering issue? Loose connection in the GT 280 female plug on the truck side of the harness or further up the chain back to the fuse box or BCM. These LED's are way more sensitive to loose connections than resistance bulbs.

Edited April 11, 2017 by abominable z71

zmnypit · April 12, 2017

If i'm understanding you correctly He swapped the entire head light assembly with another one and it still has a flickering issue? Loose connection in the GT 280 female plug on the truck side of the harness or further up the chain back to the fuse box or BCM. These LED's are way more sensitive to loose connections than resistance bulbs.

Yeah thats correct. Returned the headlight and received a new one. Even the passenger light that works flickers once you put if on the drivers side. I'm not actually in front of it so not much help.

by Payton34, Yesterday, 03:14 PM.

Anyone familiar with wiring and grounds? Today I disconnected both grounds attached to the frame under each headlight cleaned the rust and wax coating off. When I reattached the grounds There was a spark on the passenger sode as I touched the ground to the frame but driver side didn't spark. Would this be an indication the ground wire is bad on driver side?

Edited April 12, 2017 by zmnypit

SuperAllTerrain · April 12, 2017

Thanks for this! I just ordered a set of the 16 LED headlights with a harness from GEN5. I appreciate being able to see what my final look is going to be like.

You don't happen to have any pictures comparing the light output do you?

Thanks

Josh

Were did you go to order them at?

SuperAllTerrain

BringTheRain403 · April 12, 2017

I would just grind a set online somewhere (eBay or something like that) and but the harness from zmnypit

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Payton34 · April 12, 2017

I bought the headlights brand new and was sent a replacement when I thought it was the housing was bad and causing the flickering DRL. Both driverside housings I had flicker so I have ruled out the housings as bad. I also switched the harnesses sides and the driver side drl still flickers with the turn signal on until truck warms up. The first harness I had did have a loose ground wire on the harnesses plug and once I pushed it back into the plug everything worked fine for 5 days. I thought after I got a new harness there wouldn't be any more issue but I received 2 replacement harnesses from zmnypit but now have the flickering drl until truck is warmed up then it works fine.

I checked both driver side and passenger side grounds on the frame behind bumper. I ground off all rust and wax coating and reattached. When I reattached

the grounds to the frame I got a little spark on the passenger side frame but not on the driverside. I am pretty sure it is a weak or loose ground. The ground that goes to the frame behind the bumper from the headlight wire harness has not cuts I can see and is tight in the trucks plug. Could the pin inside the plug from the truck be bad and when it heats up expands and works again? I was also trying to find if another ground exists for the headlight wire harness somewhere else. Anyone have a wire diagram for the headlight wire harness? I am OCD and want to track it down. Last resort I will tap another ground wire into the harness.

Payton34 · April 12, 2017

Or I just thought since its heat related are the drl or turn signals working off a relay that could be sticking? I also found this I am going to read to look for all places the factory harness routes through truck https://www.gmupfitter.com/files/media/photo/474/2014%20BBM%20Electrical%20section_10_18_2013_WIP.pdf

Arth · April 12, 2017

Check your OEM connector on the truck side. For some reason it sounds like an intermittent arcing issue between pins. Had this happen on my 2013 Ram and it was due to moisture on the pins. Dielectric grease solved my issue. Used it on both sides.

BringTheRain403 · April 12, 2017

To that end check to made sure all the seals are in the connector on the truck side if one's missing that could cause it to be loose or get moisture...

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