on my engine "ASHTON" first off, it came with a bosch 55 amp generator and is six volt. all the wiring is still original and power comes from the amp meter terminal to its specified appliance switch to the appliance. its all routed nice and neat under the dash. the siren is energized by a solenoid with a heavy wire(looks like a twelve volt battery cable or the next smaller size wire) from the hot terminal off the starter directly to the siren. dont use anything small or you will smoke test the wire when you hit the siren!
i burned up some wiring testing another siren with small wires. they draw a lot of current getting wound up.
when everything is energized including the siren it pulls a steady 25+ amps. thats how i exercise the voltage regulator.
if your concerned about pulling too much current then eliminate what you dont deem critical for the effect your looking for.
for warning lights i have a beacon on the top of the roof, two 5" spots with red lenses on the cab above the doors and two flashing beaons on the rear grab rail and no light on the siren.
during a parade i have either my running lights or headlights, four ways on along with all the emergencey lights on which is then pulling between 10-15 amps. wind up the federal and then it hits max draw.
