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ADAHRS Harness, Left Wing

mturnerb

Well Known Member
I'm wrapping up my left wing (QB version). I ran the wires for the ADAHRS harness per instructions, but not sure what to actually do with them.

I'm planning on using full G3X system, and my understanding is that ADAHRS for these units mount on the back of the displays. So no need for ADAHRS in the left wing. I'm also planning to use the newer/smaller magnetometer (GMU 11) and based on prior threads and advice, will probably put this in the right wingtip (possibly left, but heated pitot is in left wing and I understand this has some risk of interference with magnetometer).

For now, I just tie-wrapped the wiring bundle and shrink-wrapped the d-sub pins in the harness to protect them.

I'm interested in others thoughts on a number of questions:

1. Use Garmin GMU-22 and mount in the ADAHRS location left wing? Issue here is that power wires to the pitot tube run through a conduit that's very close to this location.

2. Re-purpose the wires and molex connector? (Can't really think of anything that might work except OAT probe: there's already a hole in this location for that).

3. Possible issues with the d-sub pins shrink-wrapped (as a bundle, not individually)? This will obviously create "shorts" across pins in the molex connector but if unused I assume it won't be an issue).

Any other thoughts/suggestions/experiences much appreciated.
 
From what I heard from Steinair?s team, the GMU11 uses a CanBus interface to the G3x, whereas the GMU22 uses a serial bus. Different connector pin assignments in the harness, so, ya, probabaly major surgery to switch between the two.
 
I'm mounting the GMU-22 in the right wingtip. If you are using the Vans main fuselage harness then you'll want to stick with it rather than the GMU-11.
Using the 11 would require a huge tear up for technical reasons beyond me but Stein can explain it.

I had two discussions with Stein about the GMU 11. They advised me to run a 2 conductor shielded plus power and ground to the wingtip for GMU 11 all the way to panel: this wiring can be substituted there for existing harness wiring for magnetometer as I understand

I will talk to Stein again about the wiring.

What are you doing with the left wing ADAHRS harness / wires? Also - since I haven't gotten to the right wing harness, does it have provision for GMU 22 or are you running separate wires for it?
 
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The magnetometer(Garmin) / ADHRS (Dynon) wiring is in the left wing harness only so you will need to run separate wiring if you want it in the right tip. The wiring in the left wing is also too small gauge for a heated pitot repurpose. I ran separate 14ga shielded wires for the heated pitot in the left wing and plan the GMU22 in the left wing mount as supplied. Plan B is to extend the harness wires out to the left tip and mount it there if I have interference issues that I cannot fix by rerouting wires.
 
The magnetometer(Garmin) / ADHRS (Dynon) wiring is in the left wing harness only so you will need to run separate wiring if you want it in the right tip. The wiring in the left wing is also too small gauge for a heated pitot repurpose. I ran separate 14ga shielded wires for the heated pitot in the left wing and plan the GMU22 in the left wing mount as supplied. Plan B is to extend the harness wires out to the left tip and mount it there if I have interference issues that I cannot fix by rerouting wires.

I did the same for my heated pitot. Will reconsider the GMU22. Do the wires in the standard harness match up to the GMU22?
 
The harness comes ready to match up to the GMU22 via a CPC (round) connector that comes with the GMU22. I have not installed mine yet but it looks like a simple installation if you do per plans. I know some people have and some have not had interference with the pitot heat on so I guess it's a case of get it all together and run the test and go from there.
 
Consider not using the Van?s wiring harness

So many issue on how to make the Van?s RV-14 wiring harness work with any system install that is not an exact match to the Van?s prototype. Here is another example of just running your own wires making life a lot easier.

There is nothing magical about a wiring harness - it is after all, just wires.

Carl
 
So many issue on how to make the Van?s RV-14 wiring harness work with any system install that is not an exact match to the Van?s prototype. Here is another example of just running your own wires making life a lot easier.

There is nothing magical about a wiring harness - it is after all, just wires.

Carl

Good point Carl. I'm very comfortable with general wiring/electronics, and don't see any issues with repurposing wires that are in the harnesses where it makes sense. I just don't have so much experience with avionics and it's hard when building a kit one step at a time to have the retrospective knowledge that you and other builders do. I've already added some "extra wiring" into the tailcone and I'm putting conduits into both wings to make it easier to adapt.
 
Reading about this and thinking ahead as I will be moving to the wings section (QB) soon, I guess there is really not an easy way to use the Molex connector if we are to run shielded wire. Do most people run a straight one piece wire on those that are shielded or do that use connectors and if using connector how do you reconnect the shield ?

It would be nice to have a connector but that is another place to introduce problems I guess.

I have been planning on installing the Garmin AHAR right on the back of one of the G3X screen and install the Magnetometer in the wing (left or right)
 
I guess there is really not an easy way to use the Molex connector if we are to run shielded wire.

Stein says: "You can just bridge the shield through the molex connector on a pin if you want."
 
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