Mercedes CLA Washer System Issue

That sounds frustrating. Since both stopped working at the same time, your hunch about a pump or relay issue is a good starting point. The pump might have separate outputs for the front and headlights or it could be a single pump feeding both with a diverter valve. When you mention cable connection, are you thinking of a bad ground, a broken wire, or corrosion on the connector itself? Have you checked the fuse for the washer system? Any sign of a washer fluid leak?

Could you elaborate on the location of the relevant ground connections and the fuse assignment within the electrical system? A detailed explanation would be most helpful.

The ground connections for the washer system are usually found near the pump itself, often bolted to the chassis. Look for a wire coming from the pump that attaches to the car's metal frame. Make sure it's clean and tight. As for the fuse, check the fuse box diagram (usually in your owner's manual or printed on the fuse box cover). Look for a fuse labeled 'windshield washer,' 'headlight washer,' or something similar. If you can't find a specific fuse, it might be grouped with another system. Given the complexity, and since you've already checked the basics, it might be worth having a workshop take a look. They'll have the proper diagnostic tools to pinpoint the exact problem without causing further issues.

I appreciate the insights. Following your recommendation, I consulted a qualified technician. The issue was indeed a faulty electrical connection to the pump, as initially suspected. The repair, including parts and labor, amounted to 165€. The windshield washer and headlight cleaning system are now functioning correctly. Thank you for your assistance.