Since no one has offered a better solution I'll try to help. Attached are a schematic showing the ign switch wiring and a protection diode schematic. Grab the 12 volts at one of the RUN wires and please install a relay with built in protection diode or add one as shown. The reverse EMF spike when the relay turns on/off can play havoc with electronics if not shunted to ground. I would also add a 2 amp inline fast blow fuse as close to the tap in point as possible.