Engine overheating on Cummins ISC 350 Fan not turning

Thanks so much for the quick response.
I tried calling Freightliner in Gaffney but missed their closing time.
When I spoke to the mechanic from Freightliner in Salt Lake this morning, he had asked if the power steering was okay and said they were ran on the same. He was the one that told us to disconnect it and that the fan would run...
I will check the fan motor and filter at your suggestion and let you know. The fluid levels are good too.

I really appreciate the help.

Thanks,

Steve