I am replacing a bathroom "quad tube" fluorescent recessed ceiling fixture with a Halo recessed downlight LED "module" (RL560WH6940R). This module is the kind that comes with a male edison screw mount so all you have to do is take out the old build and screw the module in:
Here is a picture of the old quad fluorescent bulb:
The fluorescent bulb fits into a reflector housing shown here:
This reflector trim has metal springs on the side that allowed me to remove it from the recessed housing in the ceiling. I cut off the white and black wires from this reflector trim leaving the black and white wires. I then wired in a female edison screw mount piece that allows me to attach the Halo retrofit LED module.
However, I cannot get the Halo LED module to work in the bathroom fixture. I know the LED module works because when I screw it into my desklamp it lights up perfectly.
Also, I have screwed in two other LED bulbs (a 9W Sylvania and a 15W GE PAR30) into the bathroom fixture, and those light up.
Why doesn't the combination of the Halo LED module with the bathroom fixture work?
UPDATE: It appears that the ballast for the original quad fluorescent bulb is above the housing and not visible. I would have to take out the housing to remove the ballast. To remove the housing would be difficult (it is probably attached to a beam). However, I found that the Feit LED modules (1200274) work even with the ballast.