Engine Harness - Part 3 - Wiring Issue

TLDR

• Ran into a issue with ECU power, tracing wires

Details

Last couple of days, I fully connected the engine harness to the fusebox and ECU. And I tried to power up the ECU. But it didn’t work. I spent a lot of time tracing the wires.

When I turn on the EMS BKUP switch, the LED on the switch turns on with or without switching the lane lights, but the ECU doesn’t power up. I checked the lights on the Rotax fusebox, none of them lit up.

Things I have tried so far:

1. EMS BKUP off, starting cable disconnected, turn the ignition switch.
   • No luck
2. Add a incandenscent light between RE1 pin 1 and 5 (they are the power/ground pins sending power to the fusebox when EMS BKUP is on)
   • Light turns on.
   • This means RE1 pin 1 and 5 have a closed circuit.
3. Connected the ECU reader to my laptop.
   • No data at all.

I’m in an email thread with Midwest Panel Builders to debug the wiring issue. Needless to say, this has been a very frustrating process. I just want to see my engine ECU turn on since it’s such a critical (and very expensive) part of the airplane.