They prob require a min of 12v to operate. Maybe yours are wired series acting like a voltage dropping resistor.
Anyone ever done this on the pre-facelift GMC corners, the tall ones? They seem pretty cramped inside, the upper portions, and while I would be interested in sticking singular LED's in there, I worry it might look stupid with several little light sources up top and a single bigger one in the lower portion... Oh and I have a small LED T10 in the lower portion these days, that pic is still with a halogen bulb. Any insights or ideas?
I think Dave had done it on the 88 before the rebuild, but that was just the usual method, which (to me) resulted in the lights looking a little off with essentially two hot spots on a tall ass light... Any clues on that several led mod, I tried scouring the forum but so far ain't found nothing.
IIRC, that info was put up by 'TruckinAin4Sissies'. He's the LED whisperer. Don't know for how long, but he hasn't been on here for a while. You could check back into some of his old threads for the info you're looking for.
I think I've now gone through each and every one of his threads, and everything I've found with the search function, but no luck. Guess I just gotta test it out, try and find a shitty lense from somewhere and test on that, I'll update that here when I get to it this spring