2006 Freightliner with Detroit 60 Fan wont cut off HELP please

Sorry to bother people on this forum. Having a hard time getting this truck engine cooling fan to cut off.

This is what I have done.
Scanned truck, only code was the vaines code for the turbo actuator. Changed that
1. Checked fuses
2. Changed AC Dryer with low and high pressure sensors
3. Changed fan switch! how ever fan switch has two positives to it at all times. I cant figure out where or how does it ground. assumption ECM not sending ground signal. If I disconnect and apply pos and negative to fan switch then it cuts off.
4. Fan over ride inside cab is broken does not turn on or off. Do not know if that has anything to do with it.
5. I also changed the coolant level sensor. On the computer shows its full at all times.

I dont know if I missed anything else. But this is all I have done. Dont know if you guys have any Freightliner tricks. I work mostly on KWs when this happens I just change the wiring harness and it resolves the issue! I dont work on Freightliners or detroits sorry hope one of you guys can point me to the right direction