Tourneo Overheating Electric Fan Issue

Defective cable or plug connection is plausible. Is the fan clutch engaging? Have you checked the fan motor itself for continuity?

The fan clutch seems okay, but I haven't checked the motor for continuity because I don’t have the tools. How would I check continuity, and what readings should I look for? Could it be a faulty temperature sensor?

You need a multimeter to check continuity. A healthy motor should show low resistance. A faulty temperature sensor could be the cause, but the symptoms suggest an electrical issue with the fan. Given your tool situation, I recommend a workshop visit.

Thanks. The shop confirmed it was a corroded connector on the fan motor. New connector, some wiring, and 95€ later, the engine's running cool. Appreciate the help!