No, I am getting flapper control from the dash buttons, so anything that is available in the A/C system or heating core would be available for flow into the car .... everything is working well except the hot water flow to the core.
The new owner may use a ball valve to bypass the servo for the time being and find out the problem with hot water release later, at his leisure -- if I don't find it this week before the car is picked up. I still think the servo itself is OK, but some electrical or vac connection is not. Thanks for all the help guys ..... will let you know the final result.... the new owner is a forum member so he knows exactly what is going on with this system, both from my posts here and in direct email discussion etc. Ben Carter

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Ben Harrison Carter
1999 Mercedes ML320 87K
1992 Mercedes 300CE 89K
1995 Corvette 29K -- Sold Dec 09
1989 Mercedes 420SEL 99K -- (Sold 4/08)
1968 Mercedes 230S (106K) (Sold 9/06))
1976 Mercedes 450SEL 130K (Just sold - 06)
1961 Mercedes 220Sb (sold years ago)