External running light lens

As I was winterizing my 2016 Bighorn 3685 yesterday I noticed that one of my red running light lenses on the upper aft end cap was missing. Only the exposed led remained. Does any one know where to go to order a replacement lens and retaining trim? In the past I went through Camping World service to replace the led brake light assembly on the end cap - not sure if that was least expensive way to go.

You might find the manufacture's name and the part number on an existing lenses. They really snap in. You will have to use a strong hook to get it out. I found one loose when cleaning the fifth wheel. I was lucky. Heartland parts department can get you the manufacture and part number. Heartland will not stock the lenses, but the entire assembly. When one of the chrome rings went missing on one of my rear lights, Heartland sent me a new entire light assembly. I was still under warranty so there was no cost and could not believe that a part that fell off or was pulled off was covered. I asked just how much the entire LED light assembly cost, it was $24.00 or $28.00 three years ago. So a new entire light assembly maybe a quick and low cost solution.