5.0 lx just a little tweak n peak

hey does anyone know where the vac line that enters the fire wall for hvac system lead into. i cant seem to find the other end once the line enters the firewall.... do i have to tear the dash apart to get to it... does anyone have a ruff and dumb idea on the color and where the vac lines on hvac system go.... looking for a vac leak in there and have no idea where to start. thanks.