LED's may sound like a good idea. In fact I will tell you another way to do 'em that is fantastic. However the incandascent lamp in an RV absorption cooling unit MAY (Do you have an LAT switch on your unit Low ambient Temp) serve another function (That switch overrides the door switch and turns the light on full time, the slight amount of heat causes things to work better when it's cold out)
Mine was a dometic. I was full time.. I put one of these in
https://rvcoolingunit.com/Norcold-3-fan-Special-Deluxe-Fan-with-White-LED-lights-15-34-inch-wide-P5661665.aspx
Or one like it. Mine had white LED's and it not only provided light (I still kept the interior light) but kept about 3/4ths of hte fins frost free. I added an additional fan to help keep 'em all frost free.. Big help.
I wired it to the interior light circuit (NOTE be very careful doing this use volt meters to probe for power as the connection points may not be what you expect)