The WX-500 Stormscope was by far the hardest LRU to connect cables to - unlike Garmin which just designs to have DB connectors and their backshells hanging from the LRUs, they designed this fancy enclosed box to hold the connectors and provide strain relief to the wires coming into them - that means securing the wires with a clamp inside that box while making sure none of them are under much strain, then closing that all up with the wires coming out of one of the case's holes, which was an exercise in patience (and wire lacing):
WX-500 connectors installed in place
WX-500 connectors with their wires secured inside the case
Closed-up WX-500 case showing the connectors that the LRU attaches to
Closed-up WX-500 case with wires coming out the back
For grounding the GPS antennas, I'm also following recommendations to run wires out of the doublers - and I had added threaded stud inserts to the doublers for that. I'll connect the 3 GPS antenna doublers to the TAS antenna doubler, and that one down to the firewall grounding point. It's not as good as an all-metal cabin top, but it'll still give me only 60mΩ or so (with 18AWG wire).
Measuring ground wires on top of the cabin cover for connecting between each GPS antenna doubler and the TAS antenna doubler
GPS antenna doublers with grounding wires attached
As provided by SteinAir, the wire bundles were routing the CAN bus all the way to the tailcone to the GTR20, then all the way back to the panel, then to the tailcone again for the pitch and yaw servos - I wanted to shorten that, which would mean redoing at least 4 splices to connect the GTR to the GSA directly. Instead, I did what Garmin says not to do - I added a connector to the CAN bus. Worst case, it won't work and I'll have to take it out and redo those same splices, but this was way simpler and more convenient, and less resistance than the 20-25ft of cable removed from another roundtrip to the panel (according to data sheets, 30mΩ for the Molex SL connector vs 700mΩ for the GF120T-24CANB wire. Capacitance is negligible for CAN frequencies):
GTR20 connector with a CAN bus splice connector for linking to the GSA28s
I also measured and made the top TAS antenna cables (with their fancy QMA connectors) - the run inside the overhead console to the tailcone, and they turn out to be very close to the minimum bend radius when coming out of the antenna, which hopefully won't be an issue:
Top TAS antenna cables terminated on one end
TAS antenna cables terminated and connected to the GTS
Top TAS antenna cables going to antenna through the overhead console
Top TAS antenna attached to tentative ground plane atop the cabin cover
With that, I ran the GTS800 self test (by grounding pin P8002-74), and, to my own surprise, no errors showed up in the assert log! I still want to re-run this test once it's connected to the G3X, but this is very promising.
GTS install tool after self test (pressure altitude fault is expected since it's not yet connected to the GTN)
I also took the opportunity to start attaching panel components:
Some LRUs (GDL51R, fuse block, GAD29, GEA24, VP-X) attached to subpanel in the airplane
We then started running the tailcone wires through the conduits to the panel, starting with the GTS800, WX-500, GTR20 and GSA28s, and then the EFII power wires which connect directly to the batteries:
Tailcone wires going through conduits to the front
Tailcone wires exiting the right-side conduits in the front
EFII power wires exiting the left-side conduit near the panel
Next I need to actually carve the TAS ground plane opening on the cabin cover, attach those antenna doublers in place (which will be a pain to do inside the overhead console), and start final wiring of the panel. I'm waiting for the nose gear to be back on so I can safely climb inside to do wiring.
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