daughters 04 LT Blazer, the headlights will go out when
she is driving, sometimes you can switch to high and they
will come on but not always, also fog lamps won't work

Needless to say it's not safe, I'm not living where she is
so I have to coach her through it. Figured first shot will be to
replace the main headlight relay.

Any ideas outside of that is there any history of these
vehicles having headlights cut out for no reason.

 

In the underhood fuse panel:
Without removing them, check both terminals of the following fuses:
FOG LP 15amp should show battery voltage at all times.
LT HDLP 15amp should show battery voltage with headlamp switch turned on.
RT HDLP 15amp should show battery voltage with headlamp switch turned on.

Try wiggling the fuses and see if it makes the lights act up.
Post your results.

EDIT: Each headlamp filament goes through the multifunction switch before it goes to ground. This will be the next step in diagnosis if necessary.

 

will do, where is the ground connected on this circuit,

 

Can't help ya there, my 2004 schematic is quite vague when it comes to the headlamp circuits. 2000 & 2001 schematics show everything, but there's no guarantee it the same as your 2004.