bill95252

I installed a Tekonsha Modulite ZCI on my GL450. The GL has LED turn signals and running lights with incandescant brake lights. I tested all of the wires to determine which did what then installed the unit. When I was done I plugged in the trailer and got all lights flashing with the left turn signal and nothing else. So I started over. Checked each wire for function and reinstalled the unit. This time I got nothing that works and the brake lights also became the turn signals with the LED's going dark. Also got multiple warnings on dash to check left and right turn signals. Again disconnected all sensors but the LED turn signals did not work. Frustratede I went inside for a half hour. When I came back out the LED turn signals work again.
What's going on and how can I fix it so the trailer lights actually work without screwing up the GL?

Any help will be appreciated!