I changed the subject because you changed the fan and the Tstat.

If you have a multi meter, check the resistance on the ECT sensor, just below the thermostat. Get a reading with cold engine, then when the dash gauge shows 3 o'clock reading, and again when the needle starts moving up to the red zone.

Here are the readings you are supposed to get:

32F -- 7300 0Hms
68F -- 2800 0hms
104F - 1200 0hms
212F - 150 ohms

It is a nice linear curve. While checking the ECT sensor, clean the plug. Any residual antifreeze on the contacts could be bad because it will conduct electricity.

I am assuming that the fan goes on when the engine starts to get hot. If it does not, that may be relay that has failed. Turning the defrost on should start the fan, because the AC gets engaged.

If you find poor readings from the ECT, replacements are not cheap. You do not have to drain the coolant if you are any good :) Loosen the ECT, pull it out and plug the hole with a finger. Get the new one ready with the other hand and quickly thread in the new one. Minimum spillage...

Klaus
--
There is no present time, just the past and future