Nonfunctioning turn signal/running lights (85 Nighthawk)

I have an 85 Nighthawk with a hard to diagnose turn signal/running
light problem. If I activate the turn signals, they seem to work fine,
but whenever I cancel the turn signals the turn signal running lights
sometimes turn off. Not all of them, but one or two (left front, or
right rear, etc.) Doesn't seem to be the relay, and I checked all
fuses behind the headlight.

I think it might be the turn signal control itself. Any ideas? Does
anyone know where to find one of these?

Thanks in advance for any help.