Yeah, not surprised there would be people with differing results - because there are so many different LED products out there. That's why I mentioned which ones I had; the old V-LED's SMD style that are no longer offered, at least not by them. Edit - hmm, after reading back I guess that was that "other" thread I mentioned which type I had specifically. lol
I've got slightly newer style DDM switchbacks in my 2006 300C SRT8 but that's a single turn signal bulb per side setup, vs. the GMT400 with dual...plus its flashing is completely controlled by the BCM, no flasher module. I had to install load resistors to keep the blink rate correct tho, but that's with any LED's on it, unrelated to the fact I ran switchbacks.
Richard