I have a 98 contour svt, my hvac mode door knob doesnt work, I talked to a couple people and pointed me in the direction that the vacume source to the hvac control knob could be broken and I nocticed a grey hard plastic line coming from a manifold vacuum source just hanging from the intake manifold. Its pretty long and I am pretty sure this is were the controls gets its vacuum source from. I just want to know where it goes because I can't see much against the firewall. A little guidance would be nice.