In a message dated 12/24/2002 3:04:50 PM Eastern Standard Time, markblitman@xxxxxxxxxxxxx writes: > i depress the LO or HI-Defrost button on my '74 Imp to get the fan working >for a few seconds and then I depress the LO-HI- Auto button and I hear the >blend door close(or is it > opening?) and then the A/C works normally.... Mark, That is a solution that dates back to the original ATC, in fact it is written in the 68 FSM! What happens is that the vacuum check valves start to stop checking and that is the only way to fool the system into doing what you want it to do. Since it is such a long discovered problem, the only solution would be to live with it or replace the switch and all the vacuum circuits. Roy 67 Crown FDHT