The wiring never ends

I pulled most wires through the wing root openings, and trimmed some of them:

Wires coming out of the wing root openings, some of them very long

I ran the trimmed part of the GMU bundle through the wing (I'll adjust its length much later when I actually attach the GMU to the wingtip):

GMU wire bundle coming out into the wingtip

I had previously (~7 years ago) attached a circular connector to the roll trim servo, which was very bulky - I decided to replace it with a much smaller Molex SL connector, and terminated the wing side of those wires to connect it:

Roll trim servo with "mini" CPC connector

Roll trim servo with Molex SL connector

Roll trim servo connector in the wing

On the ECU connectors, I noticed the connectors had some slack because the thumb screws were bottoming out on the holes before fully seating the connectors, so I added some #4 washers to those (which was unfortunately a pain since the wiring was all secured in place already):

EFII ECU connectors with slack between thumb screw and the connector

EFIS ECU connectors after adding lock washers under the thumb screws

We then attached Clickbonds to secure various wire bundles - within the tunnel, on the subpanel, and in the tailcone:

Click Bond fasteners for securing fuel pump, GHA15 and stick grip wires

Click Bond fasteners for securing stick grip wires

Click Bond fastener to hold right-side breakpoint connector wires and coax cables

Click Bond fastener to hold left-side breakpoint connector wires

For removing the primer where the Clickbonds attach, we found out that we can use the Dremel with a 512E abrasive buff does a pretty good job and is a lot quicker and easier than manually sanding with ScrotchBrite:

Removing primer with the Dremel, for installing Click Bond cable fasteners

With that in place, I finally wired the GHA15, and then tested it (both on the G3X and by connecting the USB pigtail to a computer):

GHA15 connector and wire bundle routing

Wired GHA15 connector

G3X screen showing an AGL reading

GHA15 being properly detected over USB

The GHA15 connector is a Deutsch connector, which requires that sockets be inserted in all holes, and those without a wire need to have these little sealing plugs inserted on top of the socket (as if it isn't hard enough to insert a socket that has a wire attached to it - this required quite a bit of patience to complete):

Inserting sockets into all GHA15 cavities

Deutsch sealing plugs, which get inserted atop the empty sockets, "butt first"

GHA15 connector with all sealing plugs inserted

I also wired the fuel pumps:

Fuel pump wiring

Fuel pump wire route in the tunnel

(I also did the initial routing and trimming of the stick grip wires, but still need to attach connectors, bundle the wires with a sleeve, etc.)

I attached the EFII cables to the firewall, and realized that most of them are much longer than I'll need, so I ordered pins/sockets for shortening them:

EFII FWF cables (as provided)

Finally, I spent some time configuring logic signals on the G3X:

RPM logic signal setting on the G3X

Here's a summary of how I ended up configuring them, for now:
  • MAP ranges:
    • Normal range: Green 10-29 psi, Yellow 29-32 psi
    • When oil too cold or too hot: Green 5-15, Yellow+Alert 15-25, Red+Alert 25-32
    • When RPM 1800-1900: Green 10-25, Yellow+Alert 25-32
    • When RPM 1900-2000: Green 10-25.7, Yellow+Alert 25.7-32
    • When RPM 2000-2100: Green 10-26.6, Yellow+Alert 26.6-32
    • When RPM 2100-2200: Green 10-27.6, Yellow+Alert 27.6-32
  • Rudder trim:
    • Normal range: none
    • During takeoff (MAP >= 20 psi, IAS < 50 KT): Green -10-+20, Yellow otherwise
  • AFR:
    • Normal range: Green 12-16, Yellow 10-12 and 16-20
    • During takeoff: same, but alert for yellow

  • Battery current sensors:
    • Normal range: Red+Alert -100 - -30 and 60-100, Yellow+Alert -30 - 0, Yellow 30-60, Green 0-30, White Line at 0
    • When starting (1-500 RPM): Yellow -90-0
    • When RPM 500-1500 (alternator may not have enough output): Yellow -15 - 0
  • Backup battery:
    • Normal range: Red+Alert 8-10, Yellow+Alert 10-12.5, Green 12.5-14.8, Red+Alert 14.8-16
    • Charging (main bus at 13.5-14.8V): Yellow+Alert 10-13.5, Green 13.5-14.8
The MAP+RPM ones are trying to approximate the "oversquare" limitation from Lycoming's manual:

Lycoming graph for the IO-540-D series, showing the limiting manifold pressure for continuous operation

Unfortunately, the VP-X inputs, like pitch trim position, roll trim position, flap posiiton, etc. can't be used for logic signals - so I can't have a flaps speed or pitch trim position on takeoff alert (which are two of the 3 examples on Garmin's manual).

Time lapse:


Total avionics rivets: 177
Total avionics time: 295.3h

More avionics progress

The CAN bus issue turned out to be very simple to fix - I was plugging Garmin's GSA28 removal adapter to the intermediate breakout connector behind the panel, but turns out that only acts as a terminator if pins 3 and 4 are connected together (I missed that detail on the manual) - adding that jumper got everything working, and I then spent a lot of time updating, testing and configuring the panel:

Termination jumper between pins 3 and 4 of the roll servo breakout connector

In the process I also found out that the White Lightning power supply I'm using has an auto-shutoff (by default, after 2.5h), but luckily that didn't happen in the middle of any of the updates:

White Lightning external power supply plugged in

I also updated the light switch labels for the Ziptip Vegas (some day when I make v2 of the panel inserts I'll have the actual engravings updated, as well as adding a dimming/maintenance switch):

Updated light switch labels for the Ziptip Vegas

I also trimmed the bottom part of the center panel to run engine cables and wires underneath it, making it roughtly 1/4" narrower than the center console that mates against it:

Bottom center panel marked where the center console joins it (arrows) and offset for trimming

Trimmed bottom center panel

I then connected the baggage light:

Baggage light connected and turned on

We installed the GHA15 radar altimeter, roughly underneath the fuel valve - this gives a couple feet of distance from the GA58 TAS antenna (plus the GHA15 operates at 24GHz, so ~23 harmonics apart from the GA58 which transmits at 1030MHz), and the 120-degree cone just barely clears the landing gear:

GHA15 installed underneath fuel valve

GHA15 attached to bottom skin

I installed the roll servo in place and ran its wires through the wing.

Roll AP servo installed in the wing

To connect the wing wiring, my plan is to install CPCs at the wing root, so I drilled the holes for those:

Left-side wing root connector holes

Right-side wing root connector holes

For fuel quantity sensors, the connection is right at the wing root, so no connector is needed, I just made a hole for the single wire to go through:

Fuel quantity wire coming out of the wing root area

I also ran the light wires through the wings, which was very easy to do with the conduits. I attached the Vegas Ziptip Molex pins, but will wait until the tips are here to attach the connectors so I know the right length and can add some sleeving to them:

Wingtip wires running through the wing conduits

Molex sockets for Aveo Ziptip Vegas

The overhead console switch pod was a really tight fit around the brace nuts, so I had to trim it slightly:

Interference between the Aerosport switch pod and the brace nuts

Trimmed switch pod to clear brace nuts

Switch pod clear of the brace nuts after trimming

Last but not least, I attached the EFII connectors to the firewall and tied the wire bundle together to avoid hitting anything:

EFII wire bundle and connectors attached to the firewall

EFII firewall connectors in place


Time lapse:


Total avionics rivets: 177
Total avionics time: 281.9h

Panel turns on!

I started connecting the coax cables, with the transponder and bottom COM cables first (since they don't require messing with the overhead console):

COM and transponder coax cables running through the subpanel

The GPS antennas had too-short screws that were not going through the nut inserts, so I replaced those with longer ones (turned out MS24693C56 and MS51958-68 were the right lengths):

GPS antenna doubler with screws not coming out

GPS antenna doubler with longer screws


Bottom COM cable connected to the antenna

Transponder cable connected to the antenna

Tailcone ground wires connected

It was then the time we've all (or at least I have) been waiting for - I assembled the panel in place, and started turning on the LRUs one by one (by controlling each output of the VP-X from a laptop):

Panel frame and center section attached in place

Connecting left-side switches to wire harness

Panel turned on in place!

All of the magic smoke stayed inside!
I played a bit with the system and most connections seem to be fine, but of course there's a CAN bus failure which is preventing most LRUs from communicating - my next step will be tracing that down, then finishing up the wiring (still have to do all of the overhead console wiring, baggage light, securing all the wires, and then later the engine sensors).

Time lapse:


Total avionics rivets: 161
Total avionics time: 268.8h