G3X wiring

[bbs428]

Is the PDF of the G3X/G3X Touch Installation Manual all the documentation I need to start wiring my system? Any other documents I need to do the job?
I'm comfortable with all the wiring practices and have all the tools necessary.

Thanks!

[PapuaPilot]

Sort of. They show most of the information for almost all of the other Garmin equipment. The installation manual shows how to wire the display or multiple displays along with all of the other included LRUs and sensors.

If you have any non Garmin stuff you will need their manuals. I believe there was some additional information in the manuals for my Garmin ADSB, transponder, Com radio (GTR-200) that I used in my plane.

[bbs428]

Thanks for the reply.

I have all Garmin avionics. Gave them a call and they verified that the G3X install manual pdf was all I needed.

[Shadowrider]

GTX45R is a separate PDF. Most of the LRU'S are within the main PDF. They update it so make sure you have the most current versions, or the version that applies to your equipment. I started by reading the manual. Its like 800 pages long but alot doesn't apply to your specific equipment so it goes quick. I then made a folder for every LRU that would be installed. I then printed the interconnect drawings that applied and LRU pinouts for each LRU. Took good notes on each folder. Make sure to read the diagrams and the *notes because they have pertinent info in the notes. One comes to mine is GTR200 requires 20 gauge wire unless you are running it a certain length then you step up to 18 gauge. G3X 465 you connect a pin depending on if its a MDF or PFD.

Couple tips. Label every wire, including ground using a label maker and shrink wrap. Use a main ground bus on the firewall. I would highly recommend this one. It saves tons of time and is clean.

GB24/48 B&C GROUND BLOCK 24/48-TAB FIREWALL KIT
https://www.aircraftspruce.com/catal...07-03463-6.php

[bbs428]

Excellent! Much appreciated. Just downloaded the PDF. Thanks.
Yes lol, I have that style grounding bus.

[PapuaPilot]

Couple tips. Label every wire, including ground using a label maker and shrink wrap. Use a main ground bus on the firewall. I would highly recommend this one. It saves tons of time and is clean.

GB24/48 B&C GROUND BLOCK 24/48-TAB FIREWALL KIT
https://www.aircraftspruce.com/catal...07-03463-6.php

Yes, good tips.

FYI feel like my B&C starter hasn't been very strong lately. Today I took a look at the main wiring to the starter and engine. I found the brass bolt and nut on the B&C firewall tab was a little loose and possibly starting to strip. This bolt carries the ground from my battery to the engine/starter through the firewall, as well as providing the main ground to the B&C tab assembly. I replaced the brass bolt with an AN5 bolt and torqued it down. I didn't start the engine yet . . . maybe tomorrow.

[Meyer]

If you have a safety trim kit or battery backup kit you would need those diagrams too. Can always start without them but they have wires that go into some of the garmin dsub connectors.

[napierm]

I like PIDG ring terminals rather than fastons. Forget where I saw this but used it on my HDS installation. Get 3/8" copper tubing. Cut off a length and smash it flat with a hammer. Bend the ends to a Z to make legs. Drill holes and drop in brass machine screws from the back. I used plumbing "silver" solder, was very easy to fix the screws in place. Makes a great ground bus.

Couple tips. Label every wire, including ground using a label maker and shrink wrap. Use a main ground bus on the firewall. I would highly recommend this one. It saves tons of time and is clean.

GB24/48 B&C GROUND BLOCK 24/48-TAB FIREWALL KIT
https://www.aircraftspruce.com/catal...07-03463-6.php

[napierm]

And those darned PIDG terminals are pricey. I keep a lookout at ham fests for this stuff.

[Eric Page]

I like PIDG ring terminals rather than fastons.

I'm curious to learn why you prefer ring terminals over FASTONs. Except for physically large, high-current connections for which a FASTON is not suitable, the FASTON is easier to install and more secure than a ring terminal.

I just weighed some 0.25" FASTON terminals and PIDG ring terminals. They're virtually identical, at about 0.04 oz each. Let's be generous and assume that my scale reads 25% low, and that the weight of the wire hanging from the installed terminal increases the total weight by a factor of ten. That gives us an installed weight hanging on the terminal of 0.5 oz. Test data in the FASTON catalog (page 9) shows the minimum pull required to detach a FASTON terminal, on the sixth de-mating cycle, is 3 lbs. So, it would take an acceleration of at least 96 g to cause our hypothetical 0.5 oz FASTON terminal to detach!

Assuming you mate the FASTON until you feel it click, there's essentially only one failure mode left: a bad crimp. That's easily mitigated by pull testing each one you crimp. If it will hold with a steady pull at about 2/3 of the rated pull-out force for the wire size used (see page 8 of the catalog), then the terminal will likely detach before the crimp fails.

Ring terminals suffer from the same crimp failure mode, but add the possibility of installation errors like a missing star washer or improper nut torque (plus the added weight and installation hassle of these components), as well as vulnerability to vibration to which the FASTON is immune. If the nut holding a ring terminal loosens but doesn't detach, it can cause a high-resistance connection, which can lead to system malfunctions (possibly intermittent; a nightmare to diagnose) and heating at the stud. If rings are stacked on the stud, these problems are compounded.

Please believe me when I say that I'm not trying to start an argument, or find fault with your technique, but I think it's important that we make choices based on good understanding of the technologies we're using and the physics involved in their application.