Frankfurt. Help sought. Windshield wiper failure

Hello. Since it looks as if our holiday ends tomorrow in Frankfurt before it really started, I ask here if someone can help me in the greater Frankfurt area. So far the windscreen wipers of the windshield did not cause any problems at all. On the journey through the permanent rain from Hanover to the south I pressed the Sprueh button for the rear windows cleaning shortly before Frankfurt. At that moment the front windscreen wipers are abruptly on in the pouring rain. the highway failed. The rear wipers did not go out at first. I then got off the highway. The fuse of the front windscreen wipers was burned through. Safety changed. For a moment it went. Continued driving again fuse defective. Again replaced. Again defective. The front windscreen wipers went after the safety swap also unevenly fast. The car is now standing at a workshop. But they give me little hope. Old car. No spare parts. Too little staff There might be someone here from the region who can help me. It should not fail at the money. The car has no maintenance jam and is in good condition. Maybe there is a solution or a tip. But maybe it is just too old for long trips. That would be a pity of course.