New Andover wire harness

[Peter Restaino]

Ok I figured that so I just did the loose ones.

 

[robs ss]

I was just thinking about OP @Peter Restaino 's first post in which he stated the crimp was over insulated wire. I know what he meant, but...

Probably telling most people's Grannies how to suck eggs... Good quality crimps (see below) have 2 sets of clamps/crimps. One set that crimp on the exposed wire and another set that crimp onto/thru the insulation.
The second set stop the crimp being pulled off - and ensure the "bendy bit" is normal insulated wire - might answer your query @Fast Eddie ?
They are the only type I use, along with heat shrink over the crimped area and silicone boots over both the male and female terminals. They are available in both spade and bullet.
Of course, you need a special crimping tool for them - but they're worth it!
Cheers

 

[Fast Eddie]

I was just thinking about OP @Peter Restaino 's first post in which he stated the crimp was over insulated wire. I know what he meant, but...

Probably telling most people's Grannies how to suck eggs... Good quality crimps (see below) have 2 sets of clamps/crimps. One set that crimp on the exposed wire and another set that crimp onto/thru the insulation.
The second set stop the crimp being pulled off - and ensure the "bendy bit" is normal insulated wire - might answer your query @Fast Eddie ?
They are the only type I use, along with heat shrink over the crimped area and silicone boots over both the male and female terminals. They are available in both spade and bullet.
Of course, you need a special crimping tool for them - but they're worth it!
Cheers
View attachment 123718

Yeah, good point. The fact that the out is ‘mechanically crimped’ must obviously provide more strength / distribute stress or vibration better.

 

[B+Bogus]

A&P (aircraft) mechanic here and I can agree that soldered wire connections are frowned upon. A crimped connection is nice flexible wire right up to the terminal whereas solder will make for s stiff connection that's ready to fatigue off. It's hard not to have some wicking up the wire. Soldered connections are not forbidden and are used in some applications such as mic and phone jacks but the caveat being the wires have to be otherwise supported - not just dependent upon the terminal connection. Almost everything is a crimp type connector. Older planes may have hundreds of soldered pins in a connector but the back shell supports the wires so there's little chance of breaking. Most everything nowadays is crimped as it's faster and generally better all around. A fatigue break inside the insulation can drive you nuts chasing an intermittent.

None of the aircraft I've worked on use soldered connections, although sometimes solder sleeves were a permitted repair on damaged wiring. Some old Leach relays used solder hooks, but these must have been state of the Ark legacy use only.
Another issue with soldered joints, as already alluded to is flux residue corrosion, which I suspect is the root cause of many of the failures (IMHO, of course).
Back to the harness... British 4.7mm bullets... they're fitted into those chunky black insulated sheaths with no waterproofing and no strain relief, and the only choice is to yank on the wire to get the connection to separate. They also create a massive lump under the tank where everything, including the unused Police horn wiring has to find space.
I think I spent a day and a half re-working the harness for Jap bullets and stripping out unused wiring on my first resto.
I believe it was time well spent.

 

[YING]

I was just thinking about OP @Peter Restaino 's first post in which he stated the crimp was over insulated wire. I know what he meant, but...

Probably telling most people's Grannies how to suck eggs... Good quality crimps (see below) have 2 sets of clamps/crimps. One set that crimp on the exposed wire and another set that crimp onto/thru the insulation.
The second set stop the crimp being pulled off - and ensure the "bendy bit" is normal insulated wire - might answer your query @Fast Eddie ?
They are the only type I use, along with heat shrink over the crimped area and silicone boots over both the male and female terminals. They are available in both spade and bullet.
Of course, you need a special crimping tool for them - but they're worth it!
Cheers
View attachment 123718

Rob,
I really like those type of connectors and have a variety of the crimping pliers but have a problem with understanding what groove to use.None of the tools I have came with any info on how which slot goes with which connectors.Any help with this would be appreciated.
Thanks,Mike

 

[concours]

Rob,
I really like those type of connectors and have a variety of the crimping pliers but have a problem with understanding what groove to use.None of the tools I have came with any info on how which slot goes with which connectors.Any help with this would be appreciated.
Thanks,Mike

Mike, this Japanese made tool covers most all the connectors you need.
I use these daily. Crimps conductor & insulation.

https://www.amazon.com/Hozan-P-707-Open-Barrel-Crimper/dp/B005SUHPSW?pd_rd_w=3GSWh&content-id=amzn1.sym.2d032569-b0bd-420a-ad3a-7e5c8744bf78&pf_rd_p=2d032569-b0bd-420a-ad3a-7e5c8744bf78&pf_rd_r=BCBNJ7MHMH57620EM0XV&pd_rd_wg=hZZUu&pd_rd_r=ac6eaf19-9594-46c2-8211-854fdaf7d5d0&pd_rd_i=B005SUHPSW&psc=1&ref_=pd_basp_m_rpt_ba_s_5_sc

 

[JimNH]

Mike, this Japanese made tool covers most all the connectors you need.
I use these daily. Crimps conductor & insulation.

https://www.amazon.com/Hozan-P-707-Open-Barrel-Crimper/dp/B005SUHPSW?pd_rd_w=3GSWh&content-id=amzn1.sym.2d032569-b0bd-420a-ad3a-7e5c8744bf78&pf_rd_p=2d032569-b0bd-420a-ad3a-7e5c8744bf78&pf_rd_r=BCBNJ7MHMH57620EM0XV&pd_rd_wg=hZZUu&pd_rd_r=ac6eaf19-9594-46c2-8211-854fdaf7d5d0&pd_rd_i=B005SUHPSW&psc=1&ref_=pd_basp_m_rpt_ba_s_5_sc

View attachment 123719

When I owned the avionics shop we made lots of harnesses and having the right tooling was a must. That's really inexpensive for what it does. Other than mic and phone jacks the only soldering in airplanes is internal to the units and generally not subject to vibration like a harness. That's not to say there aren't failures inside. There was a solder joint failure that caused a runaway pitch trim in the type I flew for the last 15 years of my career. The entire fleet was grounded.

I spoke to the crew the day after it happened when they were still a bit shook up. They were ferrying back from maintenance when they experienced a 4.6G uncommanded pitch up. It was a wild ride.

Anyone interested can read what a poor solder joint did can read about it here:
https://www.google.com/url?sa=t&sou...kQFnoECBsQAQ&usg=AOvVaw1RbM9fN9c7gNmlyLCf0gqx

One of our planes was grounded in Phoenix, I was on it that day and then returned to ferry it with very tight limitations to Wilmington, DE for the fix. One of the conditions was to be heavily ballasted forward which, since I was shooting lots of skeet at the time and reloading my shells, I accomplished with 25lb bags of #8 shot that I loaded into a rental car and drove home to NH .

 

[Peter Restaino]

Wow what a story. Im an aviation mechanic but all that info on the FALCON 7X is way past my pay grade. Thanks for all the helpful tips by all the members.

 

[robs ss]

Rob,
I really like those type of connectors and have a variety of the crimping pliers but have a problem with understanding what groove to use.None of the tools I have came with any info on how which slot goes with which connectors.Any help with this would be appreciated.
Thanks,Mike

Mike
I use this type of tool. It has a ratcheting mechanism on closing and, importantly, it has wider jaws with different profiles on the left and right to accommodate the two types of crimp (my earlier post)
Look up "uninsulated crimping tool"
You insert the terminal with "crimping prongs" downward in the photo below.
One trick I have found is to bend the longer prongs (for the wire insulation) inwards a bit - helps get the process started.
Cheers