Ok so I know I've seen tons of posts on here about the AC not blowing out of the right vents and such. But I have a question about the Vacume line that comes off the intake manifold and runs across the engine compartment and through the passenger side fire wall...... What is the purpose of this line. My jeep AC blows out of the right vents except when u put it on defrost. It blows out of the front vents and defrost. Other than that, works good. Thanks for any input.