4x4 Indicator Light Stays on

My new to me 2000 F-450, PSD, 6spd, 4x4 has the "4x4" and "Low Range" light is constantly lit. I think the switch is sticky and is stuck on the on position. I was testing function of the 4x4 and it was ok for the first couple of times but eventually it stays lit even when the 4x4 lever is back into 2WD.



I checked the workshop manual and it wasn't very helpful identifying the switch location. Has anyone experienced this or can you tell me where the indicator switch is located? Many thanks.

Iconel
Vancouver, B.C.
2000 F-450, 4x4, PSD, 6spd, bone stock work truck with service deck. [image]http://s10.photobucket.com/albums/a121/Iconel/Winch/?action=view&current=Instrument_Cluster.jpg[/image]