This is one of those niggling little things that should be a snap to fix.
Pass side fog light in my '92 400E is out. I change the bulb. Light does not come on. Took new bulb out, made sure that the connector was pressed all the way down into that "slot" (if you've replaced these bulbs you know what I mean) until it clicked. Still no fog light.
Checked fuses, all are fine.
Driver's side fog lamp works just fine, as do turn signals and headlights.
Any ideas?