Among my many projects, the cab light had 24v bulbs in it. That was fine, but it also shares it’s circuit with the marker lights. I’ll eventually figure out why, but now that the circuit has been converted to 12v it makes the bulbs pretty dim.
I carefully pried the cover off of the fixture and installed a pair of 12v LED bulbs that I had bought for the coach. I originally was going to install them in my road lights. However, after finding abundant corrosion there I decided to rework all of the lights and embarked on a major project.
They are not quite as bright as the 28v bulbs, but they are plenty bright for finding something or reading a map. I expect most maps to be on my iPad anyway.
One thing I did not do was mess with the wiring. I don’t like that the cab light only works when the marker lights are on. I’m okay with it being on the run circuit, but I want the ability to turn it on independently as long as the key is in.