2025 trailer lights

[cmar225]

Been seeing a few issues with 2025’s not lighting trailer lights and now i’m having a few weird issues. I have 3 trailers, 20’ flat deck has all incandescent, no brakes and works fine. 14’ cargo all incandescent with trailer brakes and the driving/marker lights won’t light at all. Brakes, brake lights and signals are fine. Truck flashes warning trailer lights out. 30’ travel trailer, mostly incandescent with a couple leds. All lights work but truck flashes warning trailer lights out. Another weird thing, towing the cargo trailer the other day on a couple hundred km highway trip and noticed the battery volts dropped to 12.6-12.8 range (whole driving) never saw that happen before, always 13.8-14.2 unless start/stop. Then i get a service shifter warning and the light on the console shifter goes out. Then a 4wd system not available warning. Get home, unhook and then over the next day or so battery voltage slowly went back up to 13.8-14.2 as always.

Anyone have any thoughts?

I added a relay to my trailer and that fixed the issue. So my truck running light circuit is only seeing and powering the relay.