Photos of Rotax >> Dynon CAN wiring?

My new lane LEDs to light up with turning on Lane A and B for a few seconds, then off, so I'm turning my attention back to Dynon and CAN wiring.

I removed all CAN wires and started over, taking into account Bill's tips. Now my setup is:

- Blue HI wire from HIC A 6 and green LO wire from HIC A 5, this twisted par runs for 14"
- Blue HI wire from HIC B 8 and green LO wire from HIC B 7, this pair also runs for 14" where it's joined to the HIC A pair for the final leg
- Final leg is another blue HI green LO twisted par that runs 6" into the EMS-221

Powering up Start or Backup power, tuning on one or both lanes, the Dynon still shows red Xs on all engine widgets.

I then added a CAN GND to HIC B 6, jumping 6" to HIC A 4, then to a 14" EMS-221 ground. No change.

This shouldn't be so damn difficult.

You're not going to believe this. I checked the resistance on the end of the Dynon EMS-221 wiring harness, pins 36 and 37 = 0ohms. I checked at my Y junction, 62ohms. So I opened the harness connector, and ... well shit, see for yourselves.

The Dynon CAN HI (blue) is supposed to be on pin 36. CAN LO (green) is supposed to be on pin 37. Those are on pins 34 and 35. The Rotax EMS was sending data to the wrong pins, and the Dynon was listening for data through empty holes.

But here's the extra strange part: The Dynon docs say that pins 34-35 are **supposed** to be blue/green wires which are unused, and 36-37 are are **also** blue/green wires for CAN.

So they maybe make two harnesses, one for iS and one for non-CAN, and I got the wrong one? And the non-CAN version uses the same color wires in neutered positions? Why not just make one harness for all, or save money on the non-CAN one and remove the blue/green wires?? Crazy.

Anyway, I moved the pins to 36-37 and now have CAN data for miles.

I appreciate everyone's help. The "check the ohms at the connector" is what finally cracked it.

I would have run out of patience.

Dean Betz wrote:

I would have run out of patience.

These sorts of problems occur on a regular basis when building a new aircraft.
You just have to learn to go with the flow.
This is also why amateur builders are extremely proud of their creations.
Non-Builders have no idea of the ridiculous amount of work that goes into successfully completing a build.
Unless you can build full-time and neglect your friends and family (Highly NOT Recommended), it is not unusual to spend years completing the build.
When finally finished, it is something to be justifiably proud of.
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Keep at it Jason, we've got your back!