I am re-doing my dash and re-wiring everything. My Gaffrig voltmeter has the "S" (signal) terminal cut off and the only power input is to the "I" (ignition) terminal. This tells me that the gauge is reading nominal voltage output of the outboard's alternator when it's running. What if I want to know what the battery voltage is? Could I put in a switch to switch between ignition and a direct line from the battery to obtain battery volts?

Thanks, TJ

When you turn your key on without the motor running that will be your battery voltage. Volt meters only have the positive and negative terminal, you don't use a signal wire.

Thanks BadK - that makes absolute sense. You have also saved me alot of extra wiring.