Minor electrical question
 

On my 92 300E both the rear dome light and the trunk light are dead, even with new bulbs. The fuse is good and other items running off the same fuse are working. Is there a common connection between these two lights that might have come loose somewhere? Any ideas appreciated.

Thanks

I have the same problem, which I think is caused by the insulation on the dome light wires wearing out, exposing the metal wire where it is clipped to the sheetmetal under the driver's side rear pillar/headliner, & the wire shorting. The dome & trunk have a common ground according to the wiring diagram I read.

If the wire was shorted though, it would blow a fuse. My fuse is good. It's got to be an open somewhere or a couple of switches not working.

Where did you find the wiring diagram?

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.

if the ground wire was broken the lights won't work,if it's touching ground the lights will still work.

Ground
 

I wonder ,did you test the hot leg at each bulb connection? Do you have power? If so you have a ground problem,If not then I would look for the connection to be in the wire as it travels threw the door switch on into the trunk switch,If you lost connecting power at the door post (dew to a bad switch) then you would not have power at the trunk.I am not positive if your switch is wired this way but look into there being a connection of this type! JNT:silly: