Alfa Romeo Repair: cooling problem, coolant temp, lancia thema

Question
Stephen my problem is with a Lancia Thema 2.0 16v 1990 a/t and climatizer; because they are similar to Alfas I hope you can help me. The problem is with the electric fan, it was turning on when the water temp reached 100°C (it is suposed to work just over 90°C)and turn off when arriving to 90°C; I realized that the thermoswitch was worn so I put a new one but the problem is still happening. I will appreciate you help. Thank you . Luis

Answer
Have you checked the coolant temp with an external thermometer.  The coolant becomes a corrosive after 2 to 5 years, depending on type, and must be flushed and renewed.
Lastly, I always install a switch on the dash so I may turn
on the fan when I wish.