(T) Tail lights problem

Hi guys I’m new here wondering if you can help
I have a Fiat fullback diesel auto. I’m having a problem with the tail lights staying on. I’ve disconnected the battery and left it for about an hour to do a proper reset, then reconnected it and they went off for a while. After not driving it and the keys being inside the house they are somehow on. So now I’ve removed the 2 7.5amp fuses, the drivers side tail light and sidelight have gone off but not the passengerside yet, according to my hand book they are the right fuses. Any ideas it’s under warranty and booked in Tuesday but if it’s something simple I can do, I’d rather do it myself

Hi

It sounds like water ingress to me..

But its a rare beast on here.. so cannot quote any previous posters

Hope its a quick amd easy fix

Do let us know what is found