I recently bought my '90 300SE and have been trying (myself) to fix the little things that are broke. So far, so good, but I'm stuck on one problem--

Neither the driver side nor passenger side visor vanity lights (by the mirrors)work. Upon closer investigation, a previous owner had apparently tightened the screw in the passenger side visor "clip" so tight that it broke through the plastic clip and the screw itself looks like it likely shorted the positive and ground contacts. In any case, the ground side tests ok, but there is no 12v on the positive contacts for either side.

Seems like a fuse should be blown, but I could not find a blown fuse in the fuse box, and everything else electrical appears to work, (except the rear defroster). (It's not clear to me which fuse it would be anyway, since I don't have a fuse schedule in the fuse box.)

About the defroster--the timing circuit seems to work (by looking at the light on the defroster switch itself, but the defroster doesn't seem to defrost.

Questions--

1. Are the vanity mirror lights and the rear defroster on the same fuse?

2. Which fuse(s) are likely to be involved here? Are there fuses located outside the fuse box? If so, how do I get to them?

3. Any other thoughts on either the vanity light problem or the rear defroster problem?

Thanks! I really enjoy reading this forum and have learned much already...

Jeff

92 500SEL (wife's car)
90 300SE

I do not know exactly how a W140 SE is build, but most mercedes models get power for the vanity mirrors through the front cabin courtesy lamp. The powercable for the vanity mirrors is (normally)connected by a plug in this light unit. If all features of this light unit are still working, it is possible that the previous owner took out the plug for the vanity mirrors to prevent them causing any electrical damage (since the screw shorted the power...).

Some of the mercedes models do have an additional fuse box in the trunk of the car! I do not know whether the S-class has one as well, but I suppose they do.

You can check whether the rear defroster is powered or not by taking out (or just pulling aside is enough) the upholstery in the back at the left side (vertical part) and checking the connection for the defroster. Normally this is the place where the powerplug is situated in the chassis and you can check it with a "proeflampje"...

good luck

Mbenz was on target with his diagnosis on the vanity mirror lights--someone had pulled and taped the plug connector that powered the lights. Both vanity mirrors are now lighted. Thanks for the help.

Still working the rear defroster problem-

Jeff,

I send you 2 messages by mail; I hope they will help you getting back some warmth in the rear defroster...

greetingz