GLK windshield washer heater issue

I had a similar issue with my old Opel Corsa. The windshield washer stopped working in winter. First, check the fuse box. The windshield heater usually has its own fuse. The fuse box diagram should be in your owner's manual. If the fuse is blown, replace it, but if it blows again immediately, there's a short circuit somewhere. You mentioned a defective cable or plug connection, which is a likely cause. Also, even though you checked, sometimes clogged nozzles can mimic heater malfunction. Debris can block the flow, even if it seems clear. Try using a needle to clean them thoroughly. Also, make sure you're using winter-rated washer fluid; the summer stuff freezes easily. Winter fluid has antifreeze in it. And finally, make sure there's power getting to the heating element using a multimeter (a device to measure electrical current).

Thanks for the tips! Where exactly is the heating element located? I want to check the connection, but I'm not sure where to find it. Is it near the washer fluid reservoir or closer to the windshield nozzles?

On my Corsa, the heating element was integrated into the washer fluid reservoir itself. I am not certain about the GLK, but it's probably in a similar location. If you see wires going to the reservoir, that's a good sign. Honestly, if you're not comfortable probing around with electrical connections, it might be best to take it to a workshop. You don't want to accidentally short something and cause more damage. The 95€ might be worth the peace of mind.

I appreciate the advice. I checked the connection near the reservoir, and it looked fine. I ended up taking it to the workshop. Turns out it was a corroded connector on the heating element, just like I suspected. They cleaned it up and applied some dielectric grease. The total cost was indeed 95€. Thanks again!