I will go with the yellow roof running lights. Pop the covers and see if there is any water inside the covers then reseal with some Clear RTV Silicone Adhesive Sealant, need to start somewhere. All 5 of mine had water in them plus they had cracks in them so I got all new covers front and back.
2006 Country Coach Inspire 360 40ft Genoa Designer Series, Samsung 197 RR
Cat C9--STEEL & COPPER Bolt Together Radiator w/ updated rubber mounting
SilverLeaf 330 Magnum 2812 PSW 2011 Ford Edge Sport-Air Force One