To find the relevant fuse(s):
1. Consult your owner's manual: This is the most reliable source. It will have a fuse box diagram showing the location and function of each fuse.
2. Locate the fuse boxes: The 190E typically has several fuse boxes: one in the engine compartment and one (or possibly more) inside the car, often under the dashboard.
3. Check fuses related to power windows and central convenience system: The sunroof's circuitry is often linked to these systems. If you find a blown fuse in these areas, that could be the culprit.
4. Use a multimeter: If you're comfortable working with electrical systems, a multimeter can help you test the sunroof motor's power supply to pinpoint the problem.
Without your car's year and specific options, it's impossible to give you a more precise location. Finding the correct fuse will require careful investigation of your owner's manual and potentially some testing. If you're not comfortable working with automotive electrical systems, it's best to consult a qualified mechanic.