Good am all.....Chris, a good place to look is the rheostat in the headlight switch. Common issue. And I think you can still buy a new switch most anywhere...that sells car parts....
I should probably go ahead and get at running all that down as I have the steering column dropped from disconnecting the steering gear so pulling the panel would be pretty simple.....and I need to check the speedometer cable connection as well as it will start flopping about above 45 MPH.