Dawn sounds just like it looks. Like lawn and fawn.
DAHN is not like
Dan. DAHN is longer sounding. I don't know how else to say it other than DAHN. Okay, you know the word entourage? The sound the 'en' makes at the beginning? That's what the 'ahn' sounds like in DAHN.
Best way to put it... heh.
AH and AW sound nothing alike in my accent.