hi to all,
my 1970 fast back with a shaker hood not functioning properly , when the engine is off the flapper door of the shaker is open , and when i start the engine is closed since I changed the vacuum motor with a new one (the old one was not working at all).
By the way should i attche the vacuum hose from the shaker motor the the manifold or to the carburator ? I attached it to both but with the same result.
thanks for any help

 

This is normal. It's supposed to work that way.

The ram air connects to manifold vacuum:

 

thanks 2+2GT , but what is the use if the shaker closed when driving?

 

When you're driving, it's purely decoration. The snorkle still acts as the inlet, mixing cold and hot (from the manifold riser) for smooth operation of the engine in any season. When you stomp on the gas, manifold vacuum plummets, and is not strong enough to keep the flapper shut, so it opens, giving the engine that shot of cold scoop air to maximize horesepower.