'05 Endeavor 100,500 ml 3.8. The cooling fans are not turning on when reaching temp. New radiator ( because I put a hole in it oops ), cap, temp sensor, thermostat and relay works. Changed out fans- they do work with a/c on. Only thing left is ECU and water pump which was changed @ 60,000 with the timing belt. Any ideas? Also how do you determine if the water pump is functioning properly other than leaking? It never gets real hot but Temp gauge rides just a bit above normal and spits a little coolant out cap. But the fans never come on. It's pissing me off. I worked at Mitsubishi Normal il for 26 years. I like my Endeavor. Thanks for any input

 

I have the same problem with my 2004 Endeavor,
I replace old radiator with good, second hand one and fans are not turning on.
Temp. of cooling liquid is abt. 102-104*C ( 215*F)temp. gauges in the middle of the scale.
I found info that in 3,8 L SOHC engines fans should start abt. 110*C ( 230*F),
With A/C turning on, fan is not working too,
Maybe outside temperature is to low, I don’t know.