Air flow only blowing out of the defrosters on Wranglers

On 1997 through 2006 Jeep Wranglers the air flow from the air conditioning will stop blowing out of the a/c vents, and the floor outlets. The only air flow that will vent is through the defrost outlets on top of the dashboard. If your Wrangler is showing the same symptoms as the ones explained you have a vacuum leak in the a/c control head vacuum lines. To begin diagnosing the problem start with the vacuum tube that exits through the firewall between the two evaporator lines. There will be a black vacuum line that exits through the firewall and runs under the engine compartment. The leak is most commonly found in this tube that is under the engine compartment. if that is not where the leak is check all the tubes on the evaporator case and the vacuum harness on the control head.