As I have mentioned before my Trailer is a 1986 model. UV rays and temperature changes take their toll on plastic over time, and marker light lenses are no exception. The lenses on my trailer are cracked, faded, and letting water inside the housing.
I picked up some new marker lights at Walmart for less than $3 ea. I will walk you through the process of changing the entire marker light. It’s pretty simple. First remove the 2 screws, and then the red lens should pop off.
The only thing holding the housing to the trailer at this point is some plumbers puddy. Gently pull on the housing and it should pull away from the trailer, be careful the wires in the back should have room to pull out, but could catch. You don’t want to break a wire and have it stuck inside the wall where you can’t reach it.
I’m not sure if all trailers use the same color coding for their wires, but on mine green is for the power side of the marker light and white is the ground. If you are not sure you can pull off a taillight and see what colors are connected to the bulb and what color is grounded to the trailer body.
I replaced the yellow wire nuts with new ones because the old ones were rusty inside. I also put some electrical tape on the wires to keep them together (RV’s bounce and rattle going down the road). I placed some plumbers puddy on the upper edge of the marker light, this lets water run down if it gets inside, but makes a nice seal on top. It is also being used to keep the housing mounted even and tight.