The only way the light will be on all the time, that I can find is that the tractor is in calibration mode. This involves placing a 10a fuse in the f12 holder in the fuse box. When you do that it cleans out the memory of the controller and you have to follow a procedure for the controller to relearn the values from the potentiometers and relearn the voltages for the hydraulics. There is a long list of the values for the potentiometers and they have to be exactly on to go to the next step. You will need a Digital Volt Ohm Meter(dvom). Most of the specs are .4-.6v on the top of travel(tot) and 4.2-4.5v at Bottom of travel(BOT). I did the F12 fuse to mine and it was a PIA to get it recalibrated. The good news is it can be done at home. Most dealers have 0 experience or desire to help, from my experience.
If you have taken some of the values already you can handle it. All the potentiometers are is a variable resistor. By reading the output of the potentiometers, the controller then knows what you are asking the tractor to do.