Replies to This Discussion

Permalink Reply by David J. Beaulieu on April 1, 2018 at 6:46pm

"one wire at a time..."   advice given to me by a good friend and practicing A&P - and you know what? - he was right!!

Keep going at it, it will get done!

By the way...looking good!!

Good luck!!

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Permalink Reply by Gary Welch on April 1, 2018 at 9:24pm

It is a nightmare.

I don't know how i got through mine. One tip is to test subsystems as you go. I found that a 9 volt battery with some alligator clips allowed me to test the operation of many components and gauges before I did the scary part of hooking up the main battery. 

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Permalink Reply by Raymond Paul on April 2, 2018 at 3:07am

Hi Geoff, I am doing the wiring on my 701 scratch build with full MGL panel.Yes there is certainly a huge amount of wiring to put into the system. What I have done is made up the loom just for the instrument panel with all wires terminating in a plug.

Them a second loom from the instrument panel to my Ibox,Rdac,compass and AH units.

Nav lights,Landing light,strobes are on their own harness.

This has made installation of the wiring harnesses much easier and very neat ,also more practical to work on at a later stage as all major components are on plugs.

For the plugs I bought 2 boxes of plug kits off Amazon, kit has several of each 1,2,3,4,5,6 terminal connection plugs cost me £12.00 per box.

On my firewall I have used the 28 pin plug from aircraft spruce to make all connections to the engine and temp probes and MGL Radac unit.

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Permalink Reply by Todd Scruton on April 2, 2018 at 7:38am

Looks very much like mine did a few months ago. I finally got power on this last month after a complete rebuild of the airframe. All the magic smoke stayed in the wires and boxes as I hoped it would. Fortunately most of the wiring in these systems is just point to point. I had a big break in wiring, a deployment, new baby, and I really wish I had pushed through to completion before that all happened because going back to it was like starting over.

As far as taming the spaghetti monster make string tie your friend and leave service loops like it looks like you did. One wire at a time and make bundles. Make sure you keep that transponder antenna cable out of any bundles. 

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Permalink Reply by Joe Harrington on April 2, 2018 at 10:17am

As Dave says; one wire at time. Also, zip ties are your friend. Buy a 1000 pack of the inexpensive small (4”?) zip ties (I bought black ones) and VERY liberally use them. Run the first wire how and where you want. Then run the next wire and zip tie it to the first at many points. If you make a mistake or change your mind cut it off without hesitation and reroute. Then run the third wire along the first two, cutting off the zip ties and replacing as you go in order to hold the three wires together. Do this for the whole project and the wiring will look pretty good when you are done. By doing it one wire at a time, the wires will generally end up parallel rather than a twisted rats nest and be more pleasing to the eye. Another tip is to buy and use a small set of flush cutters for cutting the zip ties (same as you use for small wire cutting). BTW, the 1000 pack of zip ties were not enough; I ran out before the end and had to buy a second package..!
I hope this helps.
Cheers,
Joe

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Permalink Reply by John Butler on April 2, 2018 at 6:03pm

Geoff,

I gained my avionics engineering qualifications with the RAAF (Australian Air Force) and I am familiar with the daunting wire looms in aircraft.

If you use loose zip ties at a position on your loom where you know that wires will exit the loom, it will be much easier. That means that each piece of equipment or termination will have a junction point in the loom. If you start with, say, the power supply and you know what has to have power to it. Run the power wires and use a loose zip tie at every junction or "turn off point" on the loom. As you progress, you will find that you are actually building a wire loom or harness. The challenge is to keep the wires from twisting or overlapping in the loom.

The other tip that is a no-brainer - label each end of the wires that you run. If you don't do this, you will have to check them with a multimeter or a bell circuit.

Some simple tips, but I hope that they are helpful.

Good luck with your build.

John Butler

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Permalink Reply by dan glaze on April 2, 2018 at 6:32pm

  I purchased a label maker that prints on heat shrink tubing and labeled all wires at both ends, will make it a lot easier to keep track of each lead down the road

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Permalink Reply by Daniel Niendorff on April 2, 2018 at 7:06pm

I did the same. I highly suggest making a wiring diagram, and labeling everything. It looks rough in the middle, but once all the wire bundles are tied up, it will look great, and function as well as you plan it. I think it’s also a good idea to wire for potential later upgrades .... easy to run wire in advance, hard later.

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Permalink Reply by brad cohen on April 6, 2018 at 11:06am

No suggestions but I couldn't pass up the chance to snicker at you!
I commiserate with you though. I'd run a single wire, then swear I was gonna find someone to finish for me, then another wire, another round of expletives, another promise to find someone to finish, etc.
I finally got it done but not before a few steps back. (I keep a section of fried wire on my rearview mirrors a constant reminder)
Just run them one at a time.....
Good luck

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Permalink Reply by Gil DeVault on April 6, 2018 at 1:56pm

I don't know if this will help, but on my 601 I made the panel so I could remove it from the front, it is held in with screws. I drew ladder diagrams like electrician machine tool wires do and marked every wire, and ran them to a terminal strip. I bought a good set of wire crimpers and aircraft grade staykons to the wire ends, and pulled on every wire after it was installed to make sure they were tight. A few didn't pass, so I just did that connection over again. 

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Permalink Reply by Loren Warner on April 7, 2018 at 11:35am

Nice

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