Last question of the day till next week

[NYTOM]

I've gone all through the forums, the GRT installation instructions ,internet searches and I'd bet my last beer that my Magnetometer is in the best position and on the exact plane as the EFIS for perfect operation. "The question"
Does the wiring (6 wires) have to be run in any critical way as not to affect operation.
I have two conduits running from my panel to just past the main spar under the seats. I have a lot of stuff to run through that bottleneck of a spar, (A/P, Nav lights, landing lights, strobes, ELT, ADS-B, Trim, Comm antennas, flap motor, baggage lights etc.).
1. Can I just run these mag wires along with the others or run them along the sidewall all by themselves.
2. Would twisting the wires of the magnetometer help to eliminate any interference?
It may have been in a dream but I swear I read somewhere about keeping them away from other wires but I'll be darned if I can find it.
Promise no more questions this week!

[Jesse]

I have never separated the magnetometer wires from others, but I always use shielded wire for the magnetometer, so the wires are twisted inside the shielding.

[Bill.Peyton]

I would strongly suggest using twisted shielded wire. The installation manual for your equipment probably already specifies this, and details the proper termination of the wire. The shield should be grounded at only one end. Running the wires with other similar wires such as the autopilot servo etc. should not cause any issues. I would avoid running high power strobe wires in the same bundle. I would also keep coax carrying RF transmission separate, such as comm, transponder, adsb uat transceiver lines. I created 3 distinct bundles running rear to front.
Hope this helps

[tommylewis]

You might get better response on the GRT forum for your question but I will share my experience.

When I built my RV7a, I installed the magnetometer in the left wingtip and took care to separate those 6 wires from the strobe, landing light and gps wires in that wingtip. Everything has worked well for 7 years including an upgrade to HX units. No issues.

When I bought an RV10 and wanted to upgrade the panel to GRT HX units, I did not have a lot of options so I ran the dual AHARS and dual magnetometer wires down the right sidewall to reach behind the baggage wall with little separation between the wires. I also ran a comm coax along that same route with maybe 6 inch separation from the wire bundle. Fortunately, this upgrade has worked well also for 3 years now.

Good luck with your installation.

[BobTurner]

These wires carry high level digital signals, not small voltages. Run these wires bundled with the ground return wire. Twisted or shielded won't hurt, but as furnished from GRT they are neither. Mine works fine with no shielded wires. I would try to avoid RF like com or transponder coax.

[NYTOM]

The wiring harness that came with the Sport included very long (12 foot) separate mag wires already attached to the D-Sub. It mentions trimming the wires if necessary but nothing about shielding,twisting or anything else. Since there seems to be a lot of trouble getting these installed correctly I assumed the wiring was super critical.
Just don't want to make that simple mistake that's going to cause a lot of headaches later.
Thanks for the help.

[tommylewis]

I did not use shielded wire for the magnetometer on either airplane.