In the Haynes Manual, there is a section in the back of the book containing wiring diagrams. Another possibility for the source of the problem is the rear window ground wires, especially those going through the pillar ; they often break from the constant opening of the doors. I got the dome light back on when I fixed the right rear passenger window wiring, but the dome & trunk won't work together & my trunk light is always dim. I think the dome, trunk & rear windows also might share common grounds. Please post any progress you make.

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87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)