My 2004 SE has a problem with the stock electric cooling fan. It comes on at cold start in the morning for about 30 seconds and then that's it. It does not come on when the AC is on nor does it come on at any other time. I live in SC so it has been hot and it should have come on. I have checked all the fuses and the relay and they are all fine, I even checked using another ECU. My Ultra Scan tells me the temperature is registering, so I am at a loss.
Could the fan not be picking up a signal from a sensor or two? Is there something I'm missing? Any help at all would be much appreciated.

 

The electric fan is just an auxiliary fan. It doesn't come on until the engine hits 212 degrees, which you should never see if you've got your cooling system set up right.

 

You sure it's not your SAI pump coming on in the morning?

 

It also runs with the a.c. on if it's above 83f outside.

 

^This^

I hear the SAI pump every morning ('80s era dust buster) but have never noticed the electric fan from inside the truck. I verified though that it does come on when the compressor is spinning.