Why won't defrost work by switch?

[Mo Power]

Ok well I found out the defrost wasn't working by pushing in the button. So then I worked around with it and the only way it works is when I pull the looks like the vaccum arm and then will run the defrost and foot vents. So I'm assuming the cable isn't hooked up and I don't know where that wire has to go so I don't have to pull it by hand. Like would nice to have picture where the wire hooks on to to pull the arm in and out.

 

[Longgone]

You should have servos that work off the engines vacuum. The first thing you might want to check is the vacuum lines themselves to make sure that none are cracked or missing.