Chuck,
First thing is to verify that there is a light and wire at the dash location. Most cars did not have one. The early pre L had a yellow wire running from the fan side of one of the relays to the light in the speedo. If that is not there then you would need to run a wire from the fan relay to the dash and get a bulb holder. The best I can tell from the old wiring diagram is that this was connected to the fan with the higher temp switch.
Forest