EV-150 electrical Issue

[stevea]

I just spent the last 2 days installing a Evolution EV-150 Autopilot (EV1, ACU-150, p70Rs), and am finishing up all the connections. I have run into one electrical issue I am not sure how to resolve.
My initial Raymarine system consisted of the following:

2 e7D MFDs,
Digital Radome 4Kw
Raynet Network Switch
Seatalk ng 5-Way Connector.
There is a backbone cable from the 5 way Seatalk connector to the engine and gauge string, which are all NMEA 2000 connections.

I installed a second 5-way Seatalk connector and attached all the Autopilot components to it. I installed a backbone cable from the first 5 way connector to the second in order for the MFDs to see the Autopilot. Both my MFDs are powered via a fused toggle switch. Currently the p70Rs screen only turns on when the ignition switch is on and powering the Seatalk backbone. I did connect a power cable to the backbone that wasn’t switched, but I then got a double electrical feed to the backbone. Is there a way to get the data from the MFDs to the Pilot controller without a second source of power? Can I block certain pins on the backbone cable from connector #1 to connector #2 so that only data is transferred? I would like to view my Pilot controller for setup without having to turn my ignition switch on.
Thanks for any suggestions.