Interior or courtesy lights don't come on when doors open
 

Hello I’m having issues with my 2016 Ford F250 super duty GAS TRUCK I purchased the truck used with low miles from a friend and the interior or courtesy lights don't come on when I open the door or doors !! and the light in the bed also doesn't come on either ... I took the truck to the dealer earlier in the year and they fixxed it ... now there out again..... they said they had to replace a relay to make the interior lights come on. it lasted a few months.. I mostly use the truck during the day and I did not notice they were out again !! Can someone help me with this issue ???? thank you