Electrical issues.

You are correct that Dan did put 64 Dart parentises in post 8.
As far as what he outlined, that the problem was most likely in one of the four dual filament lamps or bumbs, that was a swing and a miss. Del got it in one shot.
I think Del picked up on the fact that only the instrument panel indicator lights were doing odd things, not the exterior signal lamps.

The bad ground wouldda been my guess too, as I've seen it make the turn signal indicators come on like that. Normally when I see that, a ground (or lack thereof) comes to mind.

.......but he's Del. what do you expect? He's a genius. lol