There were some years that Monty's did not have rear cornering lights (cost reasons?). I'm guessing this is the case on your rig?
This made me almost do some damage at a campground where I made some sharp turns at night and there was no light to see that I almost took out the rear of the rig since I could not gauge where my trailer ended - I could see the middle of the rig but the rearend blended into the dark. I might add there was also slight precipitation further impairing sight of the rig. (Having my wife go out there in these conditions was not a good option). We normally don't drive or leave a campground at dark but with this campout we planned a 10 day trip and less than halfway through the weather turned south on us (Snow, rain, sleet, cold). Then after 3 days the wife got sick, we were blowing through propane and rather than refilling the tanks again just to stay inside the rig because of the bad weather I decided "We are outta here, NOW!" and we headed home. Unfortunately by the time I got things ready for the road by myself (wife was too miserable to help) to get on the road, it was dark.
After I survived the incident with a LOT of getting out and looking, back at the house, I installed some red lamps at both lower corners and these help me "find" the back end on turns in the dark. I used matching shapes and sizes of the already present amber lights at the center and front corners of the rig and purchased two red ones from an RV shop. Then I drilled necessary holes and ran some wires to the rear running/brake lamp for illumination so that they are on when only the running lights are on (make sure you pick the correct wire to tap off). They work great and so far the night driving has been on main roads but it's nice to be able to see the rear end on a turn even in this case.
I can post some pictures of the end result, but gimme a chance to find them.
Here we go (passenger side):
(driver side):
Yup, if you "eyeball measure", they are not the same height because I did the passenger side first, then when I worked on the driver side I had the DOH moment realizing the water inlets meant I had to install this side higher. In either case, on either turn I can see them on the TV side mirrors which is what I needed.