ATC

[thethee]

thats what i figured, but the car has to sit 4-5 months for the vacuum before this happens, once its being used its fine. i have a feeling its leaking somewhere along the automatic brake lines

Doubtful, as ATCII has its own vacuum reservoir that's hooked up to manifold vacuum, leaking automatic brake release shouldn't affect your fan coming on. Suggest checking your vacuum reservoir for pinhole leaks (the soup can)

 

[jmustian]

In this case the FSM is your friend. There should be a service diagnosis schematic or list in the "heat and a/c" chapter. Looks like this in mine:

View attachment 589982
Don't expect it to give you the exact solution but it's a good starting point.

Yep. I found it. My fsm is a cd, non searchable haha.

 

[MERNJ]

Yep. I found it. My fsm is a cd, non searchable haha.

Yep. I found it. My fsm is a cd, non searchable haha.

We found after replacing the green and yellow valves, the push button control and reconnecting the broken vaccuum tabs that broke off in the “brain” (accessible through the front passenger kick plate), things came to life. That was on a ‘67 imperial Gen I ATC. See blog at https://www.1967imperial.com/post/12-things-you-had-no-idea-you-could-do-with-your-old-glasses