Not sure about the 126 configuration but it should be same or similar to the 124 setup. This is a picture of the left nozzle housing; the right nozzle housing is just off the picture. This housing is plastic and it unclips (be careful of brittle plastic clips!) to give you access to the nozzles.
Put your hood in the 90 degree position and get a pin from a sewing kit and clean out the nozzles with that. If that doens't do the trick then also use your mouth to blow thru the nozzle to clean out any dirt or whatever may be clogging it.
I had this same problem and it was due to blue residue buildup from the wiper cleaner I was using. Now I just use plain water.
'91 300E, 207k miles