There's a single connector that attaches to the headlamp housing. It provides power for all 3 bulb circuits contained in the headlamp (Hi, Lo & Fog) I guess you could have disturbed it to the point where there's a bad connection for 2 of the 3 circuits, but that seems unlikely.

Remove the headlamp access cover on the right side of the car. I'm pretty sure the plug is towards the edge of the car (rather than inward towards the motor). It will be rectangular in shape, black in color and it attaches by pressing it forward onto the pins.

There is no "clip" to hold the connector in place - good design and firm fitting pins do the trick.

Try unplugging and reconnecting the plug. If that fails to make any difference, start looking for burnt-out bulbs.

I'm pretty sure that on a 95 W140, the high beams are in the reflector closest to the grille. The fogs are below the main headlamp bulb, so you don't have a double filament hi/lo bulb. It should be easy to see if the filament is kaput.

There's a single ground wire inside the headlamp housing that provides ground to the lo and fog bulbs (I think) - it could be the source of the problem, but unless you've got moisture in the headlamp housing due to a bad seal or cracked lens, I've never seen corrosion issues inside the housings - the heat of the lamps tends to drive out the moisture.