Changed the wiring from the ECB to avionics fuse box. In the original configuration, the ECB was used to switch the power conditioner supplying power to the avionics fuses. In the most recent configuration, the ribbon cable connector for ECBs 1 through 4 were soldered to their respective grounds. Power from the conditioner was then switched to the avionics fuse box. The poor photograph and incomplete description in the MGL documents required bridging each of the ribbon connectors to determine which pins to solder together.
Attached outside air temperature sensor connections and tested in EFIS.