1978 58' MY crash pump

[hoop1013]

Looking for info that anyone can provide on the jabsco crash pump originally installed in a 1978 58 foot motoryacht. There was some sort of a diaphragm type switch installed on the top of this crash pump but when we got the boat that was just dangling by some wires. Looking for information on how this pump switches on and off and what exactly this diaphragm Looking switch does. I will try to upload some pics soon.

 

[hoop1013]

This is a top view of the pump. The nipple on top of the pump is where there should be a round metal housed switch. I'm not at the boat currently so I can't get any better pictures.

 

[hoop1013]

Beuler?