I know the Blumo didn't have a light bar but does anyone with a real cop car know how the light bar was wired to the car? It draws a lot of juice from the battery. I got mine wired up but haven't connected it yet. It works but you need to leave the engine running.
A friend here has a restored Phoenix PD '78 Fury with a Federal Twinsonic. It has a large 10 gauge wire that goes to a relay which connects directly to the battery + lug on the starter relay, and a smaller ignition + wire that goes to the relay, powering it up when the ignition is on and giving the light bar full battery power through the 10 gauge wire.