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Headlights wont turn on -- Thoughts on how to troubleshoot?

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hey guys, i have a 2015 GMC Sierra SLE.  I purchased the Morimoto Elite 35w HID kit, with the HD Relay and the Anti-Flicker Capacitor Link from retrofitsource back on 10/6/2016.  The things have been perfect ever since installing them, until about a week ago.  When I got in the truck to head to work, I noticed the headlights didn't turn on like normal.  I tried to flip the switch on and off, and got nothing at all.  I turned off the truck, got out, closed the door, waited about 5 minutes, then tried to start it again.  The lights came on just fine, no issues.  Yesterday, I got in the truck to head to a family gathering, and they wouldn't turn on again.  I did the same routine, but this time, nothing. i can't get anything at all to come on. 


I spent about an hour going through my connections to make sure a wire didn't come lose anywhere, and everything seems to be fine. I checked all inline fuses, and all fuses in the fuse boxes, and none were blown.  I can't really swap ballasts and bulbs from driver to passenger side since neither is working.  Any ideas on what i can try next?  i would greatly appreciate any help!




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I have the same setup on my 2014 Sierra and within 1 year, one of my relays went out. Then, within 2 years, the other relay went out. It was easy for me to troubleshoot because all I had to do was switch relays and if the one light not working, worked and vise versa, I knew it was the relay.

Yours will be a little harder to troubleshoot due to both your lights not working. Maybe double check power and ground connections at the battery?  Seeing you got them from  Theretrofitsource.com, their customer service is extremely helpful and the parts come with a 5 year warranty. Plus, their shipping on replacement parts is pretty fast. I'd give them a call and see what they can do to help you troubleshoot the problem.

Edited by njs2247
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  • 2 weeks later...
  • 1 month later...

Still haven't figured this out.  My problems are so random - when the headlights are in the auto position, and I put the truck in drive or reverse, they start freaking out flickering like crazy until i turn the headlight knob into the "on" position, and then they work fine.  other times, neither will come on and work at all.  i called TRS and whoever I got on the customer support side wasn't having a good day. I asked them if the anti-flicker capacitors "go out" frequently and they told me no, and I needed to test it with a multimeter.  Well, i dont think i should have to go out and buy a tool to test an item i purchased from them.  The guy just kept telling me that i have to test it and nothing else will be done until I do that.  not too helpful to me to be honest....not really sure what to try now, but it makes me not even want to drive the truck.  I've moved my ground twice now, so i dont think that's the issue, but who knows.  I don't have it ground to the negative battery terminal anymore because I have 3 or 4 other things stacked up on it for my light bar, side steps, stereo, etc.....

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I just went through a whole bunch of troubleshooting on my truck's TRS kit and I will say, I am 99% sure it is your capacitor on the antiflicker harness.  I bought my kit around the same time as you.  You probably have the old cylinder style cap.  They updated the cap to a square one which has higher capacitance.  


My lights would only work right in the manual ON setting.  In any other setting they lights would flicker like crazy.  I replaced a ballast, headlights, and relays before I figured this out because I too was told the caps don't go bad.  


Jimmy at TRS sent me a new cap and no issues since.  I did not need to test my cap...




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