[sleepy hollow]

Thanks for your response. Since I am getting vacuum at the control module, I don't think there is any problem with the vacuum source in the engine compartment.

I wish it were that simple. As far as I can tell there are no issues with the vacuum hoses or connections. So, that tends to lead me to the control module. That will hurt if I have to buy a whole new module. I'll live with a manual approach to cooling until I figure out a cheap way to fix this. Not a big deal really.