Our roof-mounted spotlight hasn't worked since we got the coach, and it finally made it to the top of my "To-Do" list. It is a RAY-LINE Model 60020, Series 135 SL. The light didn't light, and it wouldn't move in any direction. I have the original product booklet in my Owner's Manual, but it's not very helpful. RAY-LINE is no longer sold as a brand - it was absorbed at some point by the parent company ITT JABSCO. A Google search turned up a very nice video showing the innards of the light:
http://www.youtube.com/watch?v=lT9xpShO__4
Armed with that knowledge, I started poking around. Had good power (in-line fuse good) to the control switch, but found a loose power wire jumper from on/off switch to the joystick switch. Fixed that, and could hear the motors running when I moved the joystick. DW (standing outside) confirmed up and down movement, but no left or right and still no light. Went up on the roof, removed the sealed beam bulb, bench tested it - burned out. Ordered a new one from Amazon:
GE 15767 - H9405 Miniature Automotive Light Bulb - Incandescent Bulbs -...
While waiting on bulb, I removed 3 screws holding the light to the the roof. The light is "hard-wired" and only has about 4" of slack in the cable, so I had to disassemble it in place on the "slippery slope" (GV front cap). I pulled the rubber gasket off the bottom, exposing the "Left-Right" motor and gears. Removing 4 screws from the ring gear allowed me to separate the top case from the support shaft. I then removed the 4 screws in the top case, and separated it, allowing me access to the "Up-Down" motor and gears. Since that part was working, I simply cleaned everything up, greased the gears, and reassembled the top case. I discovered one difference between my unit and the one in the video - mine is missing the spring (in the bottom support shaft) that keeps tension on the "Left-Right" motor and gears. That may be a feature that was added in later production. I found the 2 screws holding the brass "Left-Right" motor bracket were backed out slightly, allowing the motor drive gear to lose contact with the ring gear. Holding the gears in proper position, I tightened the motor bracket mounting screws. This restored the "Left-Right" movement. I then greased the gears, and reassembled the bottom shaft and top case.
New bulb arrived, was installed, checked out good. Replaced the light unit on the roof, and testing confirmed operation 100% restored. 
Photos below show the bulb you need, and a shot showing the "Left-Right" brass motor mount and ring gear on my unit.
Topic: RAY-LINE Roof-Mounted Spotlight, Repair of