Where is the Vacuum Reservoir Evans Tempcon Dash

[FTCMCB]

I have a 2006 Forest River Georgetown. The Evans Tempcon blower is defaulted to the the windshield louvers. The blower works and the temperature selector is functional. I am sure it is a vacuum leak or loss. What I am not sure of is where the black ball plastic ball about the size of a grapefruit is located.

Any assistance locating this would be awesome. If I find it I will repost with pictures and troubleshooting guides.

[FTCMCB]

In my case the fault was where the Evans Tempcon plugs into the F53 chassis Vacuum Reservoir. The fitting cover has rotted out since it was installed in 2006. My quick fix is duct tape. It works till I get a part, I have hot and cold air from all ducts again

[FTCMCB]

Here is a picture of the F53 Vacuum Reservoir located in front of passenger front tire