Peugeot 301 Overheating Electric Fan Issue

Overheating is definitely not something to ignore. Since you've checked the basic stuff, focusing on the electric fan is a good idea. Have you tried checking the fan relay and the fuse associated with the cooling system? A faulty relay or blown fuse could prevent the fan from kicking in. Also, do you have access to a multimeter to check for voltage at the fan connector when the engine is hot? That would help confirm if power is actually getting to the fan.

Thanks for the quick response! I haven't checked the relay or fuse yet, that's a good point. I do have a multimeter, so I can test the voltage at the connector. Do you know where I can find the specific relay and fuse for the radiator fan in my 301? Also, what voltage reading should I expect at the connector when the fan should be running?

The fuse box diagram should be in your owner's manual, or you might find a sticker on the fuse box itself. Look for the fuse and relay specifically labelled for the radiator fan or cooling system. As for the voltage, you should be seeing around 12V at the connector when the engine is hot and the fan is supposed to be running. If you're not getting that, it definitely points to a wiring or relay issue. Given the symptoms and your checks, a defective cable or plug connection of the fan component is the most likely cause. I recommend visiting a workshop to get it checked.

Thanks a lot for your help! I checked the voltage as you suggested, and it was indeed very low. I decided to take it to a workshop. It turned out to be a corroded connector, just as we suspected. They cleaned it and replaced a short section of damaged wire. The total repair cost was 95€. Everything is working perfectly now!