@Boston Mangler something I noticed on mine was that the turn signal bulbs were very dimly lit while the high beams were used in DRL mode. I suspected the turn signal bulb and side marker bulb were cross wired (my side marker bulb never comes on). So I asked for a replacement harness from AliExpress. Was hoping that plugging those on would solve my issue and if not buy the harness from eBay. Well it looks like you used the eBay harness and are having the same issue.
I unplugged my side marker bulbs from the sockets and walla the brightness of the high beam in DRL mode for passenger side increased. Might want to check if yours is the same, the turn signal bulbs are very dimly lit and difficult to spot in daylight.
I tried to rule out vehicle harness grounding by temporarily plugging in my old headlights, swapped pigtail harness left to right and even plugged in a spare used 2013-2015 style headlight assembly to rule that out… without any avail.
How did you turn off DRL? I don’t have the option on my dash or center stack. Tried looking around.
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Thanks for the info.
Yes, mine is doing the exact same thing.
Turn signals very dim also
I just checked and even though the look the same and have the same socket, the 2010 and 2013 bulbs have different part #s
Maybe they have different draws for some reason due to the HIDs?
This is a bit out of my wheelhouse, so hopefully others will chime in with their .02
I will try to swap the bulbs from my 2010 lenses in later on and see if that makes a difference
Did you see turn signals and markers for a 2013+ or for the actual year of your truck?