The bus bar must be lifted evenly so all the tabs come out of their slots at the same time. The fuses connected to the bus bar are hot at all times. To make one key-switched, cut off its tab, AND the metal below/around the tab so a wired terminal can be inserted to that location.

See also:
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https://www.fleet.ford.com/truckbbas/non-html/1997/c37_39_p.pdf
http://www.bbbind.com/free_tsb.html

Owner caption July 2006 · Photo 1346 of 5000