Mercury ignition switch

[Frank Acampora]

I am replacing a Merc tracker 40 on a 24 foot pontoon with a larger engine. The ignition switch is push to choke and has seven (7) terminals:

"B"
"M"
"M"
"C"
"I"
"S"
"A"

Now, I know that "I" is a switched source of power but is "A" (accessories?) also switched and only powered with the key turned to run? Or is it like a car with the key turned backward to power the accessories? I don't have the key, the darn thing has a spider's web of wiring, and it is difficult to trace. Never saw a 7 terminal switch before.

Thanks!