I am looking to add an electric fan set up to my tbi truck. I am curious if any of the guys that burn chips know if there is circuitry in the ecm for a fan.

 

No. You would have to do a stand alone setup. To do this you run a coolant temp switch that grounds when the coolant reaches the switches tempature. This completes a circut to actuate a relay which in turn supplies power to the fan. You can also run a toggle switch in the passanger compartment to have manual control.