Thanks guys, those are just the facts I needed. Thanks for the warnings as well. I've got a Westach V/A meter that seems to work fine for both voltage and amperage. I also just got a copy of the book John suggested, good stuff in there but I've just started to read it. I assume that hooking up the "C" terminal to some positive voltage controlled by the master switch is the right thing to do since the Rotax schematic stated the need to be able to break the circuit to the "C" terminal so as not to drain the battery after engine shutdown.