When I first purchased my 1978 the light on the dash indicating the emergency brake was on--stayed on, so I removed the bulb (brakes worked fine). Now I am replacing the emergency brakes and handle the question is how does this indicator work and where is the switch located as I would like to replace the bulb?

The switch is located behind the console where the brake handle is located. You could have a bad switch or the switch could be misadjusted all this time. It has a button that is activated by the brake handle.

This light is also operated by the pressure switch in the combination valve to serve as a hydraulic warning light.