HI just bought my first ever mustang and i was wonder why my air/ac isn't coming from the front vents but coming from the defrost vents i assume this has something to do with it? if so what are these lines called so i can replace them also a diagram would be nice thanks for check this out
You've lost vacuum to the hvac diverter inside the cabin. See the small black vac line loop in your first pic top left, that's the line that goes inside and feeds the controls and diverter.
In your hand is the vac source for the smog pump diverter and bypass. You can replace the cracked plastic lines with standard vac tube.
The following are diagrams courtesy of Tmoss & Stang&2birds
Vacuum diagram 89-93 Mustangs
HVAC vacuum diagram
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring; http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.