Well, that dash sound was weird.
I did take truck to local mechanic and he heard the noise. As if continued I was going to have this looked at further. It was a muted sqeaky noise.
It was there for weeks at a time. Then would go away. Then come back. Seemed to come from just above the ash try or thereabout. It did not sound like anything coming from the heater/fan. But who knows.
It is gone now for quite awhile.