Dash Lights dimming

In my 1992 SVX, the dash lights are changing their brightness on their own! They go from full-bright to dim in one moment, but increases from dim to Bright at a gradual pace (almost unnoticable). It is most prominent on the shifter lights (on the dash... noticed another thread with a different problem... console shifter lights).

My wife is the primary driver, she also reports that the headlights also seem to have this behaviour. I will take the car for a test drive this evening to check it out for myself and update the thread later.

It might be the connector for the dash circuit board? Any instructions on getting to that connector and testing it?

Thanks,