attention car guys!

Ok, got an issue thats driving me bonkers. cant figure it out for the life of me.

I have no tail lights. Brake lights, Turn signals and 4 ways all work fine, but the running lights, ya no go.

Ive checked the switch, its fine. checked for continuity, its fine. checked the fuses, fine. Checked the voltage coming from the battery. its fine too.

I cant figure it out. and i cant drive at night.

any ideas from anyone?

its a 1999 1500 Chevy Suburban 4x4.

only thing i can think of is an open in the line between the switch and something or a bad ground but cant find either...