Remember that not all disconnect switches are created equal. Some of them only have around a 200 amp capacity or less, while others have a surge current capability of 1,000 amps or so. If you're running a 6 volt system, don't skimp on current capacity, or there might be enough voltage drop across the switch to make the engine crank slowly or have a "crank- - - -no start" situation due to low voltage at the coil. If you've got any fancy electronics like a digital clock, GPS or a high end sound system onboard, you might need to wire in a "keep alive" circuit that bypasses the disconnect and provides a constant hot and ground to that device. Otherwise, you'll erase all the pre-set information every time you switch the power off.
Jerry
