[README] Crimp notes & splice connection

Hardware inside and outside of the ECU
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kb1gtt
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Crimp notes & splice connection

Post by kb1gtt » Sun Mar 20, 2016 9:53 am

Often problems are caused by poor crimps. Crimp connections can cause heat, or when you have a capacitive based circuit driving an inductive device, the resistance in between can cause a tank circuit, which causes all sorts of problems. The below videos help show the differences of a variety of commonly used crimp tools.

A quick summary of the video's is that using the proper crimp tool will survive a much better tug test force. This better tug test force is an indicator that the crimp quality is better, as it will have lower contact resistance, and better resistance against long term corrosion. The tug force for this particular connectors is 192 lbs, while if using the wrong crimp tool could be as low as 12lbs. If you are doing just a mild pull test with your fingers, you won't notice a difference in the tug force.

-- TE training advanced video 20 min

See about 11:00 min for crimp range
-- TE training how to use crimp tools 5min
-- Guy testing with proper tool 193 lbs
-- Guy testing with proper tool slower pull 192 lbs
-- Guy testing with Harbor freight ratchet crimp tool 83 lbs
-- Guy testing with Klein Crimp 12 lbs
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Crimp / splice connection

Post by kb1gtt » Sat Jun 15, 2019 10:52 am

So you have a nice ECU harness pigtail, and you have an injector harness to connect to it. How should the two wires be connected.... loosing your car or house due to electrical fire sucks. I suggest considering using a reputable and good crimp tool. The TE 58433-3 crimp tool covers a huge array of connectors, and this tool is reasonably low cost. It's $121 as of writing this. As well it's a once in a life time purchase.
https://octopart.com/58433-3-te+connectivity-40197095

Then I would suggest a connection which this tool can crimp, perhaps the knife connectors like the TE 32447.
https://octopart.com/32447-te+connectivity-42927080

If you are concerned about saving pennies, there is also the TE 34071
https://octopart.com/34071-te+connectivity-39388690

As well an environmental seal can be obtained with shrink tubing. Adhesive-Lined Polyolefin Heat Shrink Tubing helps keep a good long term connection.
https://www.3m.com/3M/en_US/company-us/ ... 7497&rt=r3
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Re: Crimp notes

Post by russian » Sat Jun 15, 2019 12:55 pm

Some links from relevant Slack discussion:

the bible of motorsport wiring https://www.rbracing-rsr.com/wiring_ecu.html

Softer butt connectors for better crimp
https://www.amazon.com/Connectors-Event ... B071L6VDLK

Solder sleeves crimpless open question if we like them
https://www.amazon.com/Shrink-Solder-Sl ... B01M1032A7

Tools:
https://www.amazon.com/gp/product/B00OMM4YUY/
or
https://www.amazon.com/gp/product/B0751991LP/
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Re: Crimp notes & splice connection

Post by kb1gtt » Sun Jun 16, 2019 1:08 am

I once had to deal with a multi-million dollar issue due to poor crimps. AKA equipment was catching fire, which got expensive quick. We ended up loosing many customers. It sucked. At least it was not my equipment, I was dealing with someone else's sins. Any how based on what I learned form that, I would suggest against generic crimp tools. There are many small quality improvements. I spend allot of time in our lab with microscopes, thermal cameras, temperature probes, and probably the most notable was the tug testing tool. We had a semi generic connector which was demanded by our customer. I had to find a crimp tool which preformed a proper crimp. Most crimps should hold around 90 lbs. The OEM crimp tools had no problems, but pretty much all the generic tools failed the tug test typically around 30 lbs, when they should have held 90lbs. This resulted in excessive heating and in our case electrical fire.

Any how, I suggest the OEM tools, because electrical fires suck.

Shrink tube should be installed after the crimp. Those combined things are not worth it. Take the extra 10 seconds in labor and shrink tube after the crimp has been made.

Same goes for those solder / shrink connectors. It is very difficult to get the solder to flow and not damage the shrink. So just solder it then shrink it.
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Re: Crimp notes & splice connection

Post by russian » Sun Jun 16, 2019 1:20 pm

open barrel splice kind is what I am curious to try. https://www.te.com/usa-en/product-485043-1.html

I guess I can get one of these amazon tools and hang something heave by the resulting spliced wire for a pull test?
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Re: Crimp notes & splice connection

Post by kb1gtt » Mon Jun 17, 2019 12:58 am

Hang test is probably close enough for our needs.
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