This diagram shows when vacuum is applied to which setting. Your problem is the supply line(black) vacuum hose comming in from the firewall. Or the reserve tank, both are under the hood, the supply line comes from the intake manifold on the top of the engine, goes to a check valve then to the reserve tank, and into the control head inside the car. This or the control head is the problem, do you have a vacuum tester? It's a hand held pump with a vacuum gauge on it. Attach it to where the black supply line is, pump it up to 18-22 hg, system should now switch to any desired airflow output, if not the control head is NG!
Sunday, September 6th, 2009 AT 9:36 PM