detroit series 60 fan stays on

Have you done all the checks I suggested last week?

 

find somene with DDDL, Laptop and adapter to hook your truck and check all the components. it is 20 minutes deal to find the problem...

 

just an example - auxialy inputs for A/C fan actuation ore fan override button.

 

edit........

 

These are both "Non volatile memory" faults with the ECM. They are displayed as flash code 53. Prior to software level 9.0 it used to bring the amber CEL on.
The only cure is a new ECM.
An ECM with an active code 53 may operate normally with no problems. You only know it is there when you connect a reader to check codes.
I have also seen ECM's develop other symptoms with this code. These may or may not be related to the code 53. I tend to consider an ECM with code 53 as suspect, or on its way out.
Did you check the inputs and outputs with the reader?
What was the reader?

 

Mine used to come on too soon at around 175 degrees and now it stays on even under 100 degrees. ..

 

mine came on and stayed on. I could hear the fan especially driving from dead stop as i would increas rpm before switching gears. Checked fuses - all good. opened the hood and saw that fan was spinning hard even though coolant is cold... Finally realized that a wire came off the engine fan switch... Once i reconnected the wire back to the switch, the engine fan got shut off. Fixed)