I did some searches before writing this, so I apologize up front if this question has been asked. I hooked up my trailer wiring harness this weekend so I could pull a 19ft boat. Would have had the dealer do it, but they couldn't fit me in. I know I still have to go back for the programming. My brake lights and signals work fine, but the tail lights don't come on. The boat dealer said the lights all worked, although I never noticed since everything was done during the day hours. I checked the fuses and the ground and all are good. The trailer does have LED lights and I am wondering if this is the issue. I will hook it up to a friend's truck tonight to see if they work as designed, which should point to something in the LR4. If it is due to the LED tail/side lights, is there a simple solution? Thanks in advance for any help.