Flourescent Fishing light replacement converter

I have five of these 12" green fluorescent fishing lights from Optronics and am trying to figure out what type of converter or resister is used in-line between the light and the 12v source. Four of the lights are no-functioning due to corrosion in this housing, but work perfectly with switched on using the power adapter spliced from the one functional light I have. I've e-mailed the manufacturer and those turds are apparently soooo busy they can't return a freakin e-mail...grrrr..any help or ideas would be great.

Here's the light:

http://www.innovators-search.com/product/91348/