this might require the use of a diagnostic scanner. i will do my best to help you out.
you will need to know what the pcm is reading for engine temperature. if the coolant sensor is bad and the pcm thinks the engine is cold, it will never activate the cooling fan relay.
did you jump the cooling fan relay? if you did and the fan worked than we know the relay is not being activated by the computer.
This could be bad pcm, wiring or a bad coolant temp sensor.
the pcm will generaly activate the fan relay at about 215 deg F.
if the engine is running about 220 deg and the fan still hasnt turned on and the cts is giving the correct signal to the pcm , than the driver in the pcm could be faulty.
you will have to backprobe the back of the pcm at thecooling fan relay control and see if the pcm is giving the signal. If it is a good signal coming out of the back of the pcm than it will be wiring and you will have to open up some harnesses for find the open wire.
I hope this has helped you and i will assist you more if you need it.
I appreciate any positive feedback