what turns on the rad fan?

[coltkelz]

is there a single output that sends a signal to turn on the rad fan from the ecu or mpi relay or is it just done by the temp switch? i have looked at the diagrams for them and cannot find anything

 

[Blacked-out]

Check for the ect, to the ecu. To the fan?

 

[luv2rallye]

1g is a thermo switch at bottom of radiator. 2g has ECU controlling fans based on ECT, A/C, and car speed.