As I indicated above, I didn't change the climate control settings while testing. I did pull a vacuum on the main cabin line and it held with no loss for 2-3 minutes. Perhaps the first thing to try tomorrow would be to change the climate control settings and see if that makes any difference.

What has me puzzled is that the valve appears to work with minimal vacuum, as does the switch (supplying plenty of vacuum to the valve) but, couple the two and nada.

Thanks for the imput.....Jim

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2005 C240 4matic wagon (daily driver)
87 190D - 225K (on loan)
85 190D - 312K (on loan)
2011 Subaru Legacy AWD (Wife's)