The wiring is there for the light; I installed one in my unit last year. Took all of 15 minutes. And amazingly, everything is marked, making it that much easier. Standard light kit from Lowe's or Home Depot. All I did was take out the standard 40W bulbs and put in LED's. Good luck.
Travel Well, Travel Safe,
Jim & Linda Tator
2013 Crusier CF34SS GMC 3500 8.1L Dually
154 nights in 2013 - 4,370 miles
178 nights in 2014 - 5,082 miles
365 nights in 2015 - 6,040 miles