Greeting to all .. 2005 Silverado Z71 4X4 Ext cab .. I've been looking at updating my tail lights (plus a few others) to LEDs. I thought that they would be a straight swap-in, but I'm now convinced that the conversion may involve resistors being added and a flasher module being swapped out. To further muddy the water, when I use my buddy's trailer (has the whole LED package on it), everything works fine and I have no issues. What is the REAL deal? Thanks in advance ..