I need both B+ and switched B+ for all the electronics. I fed a temporary run of #10 from the battery, through the firewall to the driver's side kick panel (temporary because I will be bringing a heavy line to the amplifiers later). Switched B+ is a bit more of a trick though. I discovered the cigarette lighter is a true ignition switch turning immediately on and off with the key. I don't smoke anymore and the plug is covered by the radio head so I cut the switched line from it and fed it over to the coil of a 30A relay:
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