'70 Dart 392 Project; what direction?

Well I'm ready to start the engine I believe, but after going through all the sensor calibrations and fuel/ignition settings, first time I cranked the engine tunerstudio shut down. Its apparent that my "12v switched" wires I used for the ECU/FUEL/02 sensor/fan relays go dead when the engine cranks.

Anybody have a good source off the top of their head for a 12V switched source that doesn't go dead when the engine cranks?

Thanks in advance!

Mike