okay it's not diesel related but its a diesel truck...
I replaced the resister at the fan motor.Still only off or high on fan......
trk is ford w/7.3 non turbo international.
any ideas??????? thank you....

 

Maybe check the connectors. There should be a "multi pin" connector and a single pin connector from the harness to the motor. on my trucks, the single is the "high leg" and the multi pin is low and both "medium" speeds.