I Have Two Battery Switches But If I Cut Either Of Them Off Both Eng's St Ill Have Power. Could Something In The Dash Or Cocpit Be Running A Connection

Power to keep running or power to crank?

both

Something could be connected on the hot side of the battery switch, connected to the starter hot terminal or directly to the battery. Some boats are such a wiring nightmare that who knows were the power is back feeding from.

efi so i guess i have to fig it out thanks

Sounds like the starters are wired direct to batteries + to me.
The main AC buss usually comes off of the starter.

The "right" way to wire the switches is batteries + to switch, and then switch output to starter.

Check this thread out. Is this what you have?

forgot something the tread

It should be pretty easy to trace down, see whats bolted to your positive side of your batteries and trace them down. If they only have a run to the perko switch than you should be able to shut them off. If they have any other wires, (starter, alt, trim pump) then you could have power runnning off one of those for your motor. The standard 9 pin Merc harness runs power to you dash, that harness is probably connected to your starter or altenator.

oops,

here it is http://www.offshoreonly.com/forums/s...ttery+switches