Here is a link to an online manual of the 126. http://mb.braingears.com/126_DISC2/program/matrix.htm

One thing you can try to narrow down the source of the wiper issue: Turn on the headlights, and then activate the windshield washer pump and spray windshild cleaner on the windshield. The headlight wipers should activate when you do this. If they don't move, your looking at an electrical issue other than a bad wiper motor.