LED tail light signals will not flash when lights are on

[calgary72]

I installed LED plug and play tail lights from LMC and the signals will not flash when the lights are on. I installed an electronic flasher (with ground wire), also from LMC. I also installed new LED headlights (in case that makes a difference).

I understand that flasher issues are often related to bad grounds. After it didn't work the first time I relocated the flasher ground and took apart the taillight assemblies and sanded the contacts with the frame and cleaned and sanded the inside of the plugs. Still would not flash when lights are on. Light goes on, just does not flash. I re-installed the old bulbs and works fine.

Can anyone help? Thank-you for any suggestions. I searched the forum and couldn't find anyone who had the same problem.