Spent afternoon reading the schematics sent to me by Pipstrel until I understood all the wires and connections to the Engine, FuseBox, Pipistrel's engine wiring harness, Pipistrel's 912iS keybox (used to manage power based on switch settings and keep Lane A and B's grounds isolated). The keybox connects to the main wire harness 37pin connector and to power and ground wires also coming out of that same wire harness (Don't know why they didn't put the 912iS Keybox as part of the Pipistrel solenoid and fuse board. Would have saved lots of wires). Also browsed the web and learned the CAN bus connections. The Rotax has 4 CAN buses, one display and one maintenance from each lane. The two display buses are connected together (CAN bus is a 3 wire (CAN H, CAN L, GND) serial bus with all Master/Slaves wire ored together so you can connect as many devices as you want on the 2 wire bus) and then connected to the Pipistrel 37pin break out board for the Dynon 221 EMU (i.e. the CAN Bus connection into the Dynon). Fuel Pressure sensor, Voltage and current sensors and water temp sensors also connect into this breakout board. Pipistrel recommends connecting the other 2 CAN Maintenance buses together and then connecting them to a DB9 connector. Rotax does not recommend connecting the 2 maintenance buses together so I think I will purchase another DB9 connector and keep them separate and mount the 2 DB9 connectors on the side of my instrument panel.
