70 GS455 Hi Beam indicator

Wanted to mention an odd problem I had with my 70 GS455. I have being going through the car (recently purchased) and the high beam indicator lamp was not working at all. Figured I needed to replace the lamp in the instrument panel. Started the car the other night had high beams on left it idling for a while, the beam indicator started to work after 10 mins, along with the ash tray lamp ? Car was idling high before I reset the throttle, figure it is a loose connection or possibly the voltage regulator output was higher than normal and triggered this event. Anyone heard of this before ? All the other accessory and instrument lamps worked fine before and after this happened.