Illumination problems 560sl

[bhatt]

Hello,

Have an '87 560sl and some of the interior illumination doesn't work..

In the dash (above the radio) are three switches in a row: rear defrost, antenna, and dome light. All three switches control the respective devices properly, but only the dome light one lights up at night. The shift indicator light is also out.

A few questions:

1. Pulled the antenna & defrost switches. Found a light tube plugged into the back of each switch (looks like this system has the fiber optic system same as my W126). Does the dome light also use this system or does it have its own bulb? If it uses the fiber optics, it looks like I have a break in two of the lines.

2. How to troubleshoot this? Where is the fiberoptic cluster? Behind the radio or behind the climate control? Other than looking for obvious "broken" fiber lines, are there any other ways 2 lines can fail while the other works? I assumed when the bulb died that all the lines went dark -- have never seen one still work.

3. Is the shifter light separate from this system? (ie. does it use it's own bulb?)

Thanks! Searched the EPC, W107 service CD, and the past posts here but can't find anything.

Neal