Radiator Fan

Have you checked the coolant temperature sensor?

No, I just checked the fuses and replaced the relay and then the sensor or whatever it is called that goes from the fan wiring across the radiator. I took it off and looked at the diode and it looked okay, but not sure it that was the problem or not. So do you think I should check that coolant sensor first?

I am sorry. I never replaced the sensor that goes across the radiator, just looked at it.

That was probably the fan relay or resistor for fan .The coolant temperature sensor tells the ECM to turn the fan on.

If the truck is not overheating, how do you know the fan is not working? These fans are not programmed to come on until higher than normal temperatures. Do they come one when the air conditioner is turned on?
It is also a two speed fan system so it could be only low speed that is not working.

Here in Ohio it has been extremely hot in the 90's and after driving for hours and stopping, I check and the fan does not come on. I will change out the coolant sensor. I did ready some interesting tips from your site in reference to fuses. There are several small fuses where the test light only lights up when I touch one side. According to your article, both sides should light up. So I will replace those fuses as well. Little by little I am walking through this to find the culprit. My air conditioner quit working suddenly last month blowing hot air. No leaks pressure good, just not hearing the compressor clutch clicking on. Not sure if these are related or not, but a coincidence. Thanks for your help.

There is a controller that goes out often on these cars, it is located near the engine.

here is a wiring diagram so you can see the path. Please check the fuses shown here as well and get back to us so it will help others.