Even the "error free" led's (never had any in my hands to test out, but I have no idea what would make them "error free") can have issues. As with anything electronic there can always be a couple of bad ones in the bunch.
Joe02, drop me a message when you get a chance & I'll do my best to make it right with the led's you're having issues with.
Even though I test every led before I send 'em out, once in a rare while some will do crazy things when installed in the vehicle. Not sure why or what makes it happen, especially since I generally torture test some of each batch of my plug-in led's by running them at 15v for a few hours.
They're not likely ever going to see that high of voltage in a vehicle unless you have an adjustable voltage regulator on your alternator that allows for that high voltage.
The LED's sold in most auto parts stores, big name brand online led specialty stores, etc all come from overseas & are likely made in the same factory by the same people... some of them just get put in a shiny package with a cool graphic that you get to pay 1000% markup on.
It's just not economically feasible to produce that kind of stuff in the US... they basically have slave labor & work for near nothing over there & many of the components are already made there so it's cheaper to have parts made there & shipped to the US to sell at inflated prices.
With unions & health insurance & stuff like that, a led that costs $1 from overseas would probably cost $9 to make here
Sorry, kinda got off topic there...
My plug-in LED's are from overseas (probably from the same manufacturers as the others) but since I'm NOT a business, just a guy helping out his buddies in the ranger community, I don't need to have fancy packaging or marketing or all that stuff so I can offer them at pretty reasonable rate.