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Discussion Starter #1
While working on the the Elise, we had to do some wiring to change injector clips. My mechanic asked how I wanted the connections made. I asked how he was most comfortable and skilled doing the wiring. We discussed the ongoing debate and merits of each, but he preferred to solder. He also requested I post pictures of the proper steps to a connection.

1) press the strands of both wires together then wrap the joint tightly with a few inches of a single strand tied at the beginning
2) Solder with high quality lead based rosin core solder.
3) shrink wrap
4) wrap with electrical tape

I'm sure there are other ways, but I liked his wrapping technique.
 

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A crimp connection is a connection living on borrowed time. A correctly soldered connection will still be good, long after you are dust. Crimp connections have the advantage of easy removal. Soldered connections have the disadvantage of taking longer to master the skill. A cold-soldered connection is worse than a crimp. The only thing worse than a cold-soldered joint is two wires twisted together and wrapped with tape.
 

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i dont usually crimp, but when i crimp, i used a deutsch connector + pin/socket.
and trust me nothing, and i mean NOTHING beats that....
 

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Er, EE.engineer,
Had one of those fail on my harley, going to the ignition module. Galvanic corrosion caused the failure. The first rule of connectors, no connector is truly waterproof, wicking affect can be amazing. I have seen water wick 75 feet UP coax.
 

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Assuming the technician is skilled at both, then soldering, hands down... Takes longer but way less chance for failure than crimped wires.. Especially in applications that involve vibration and movement of the wires.
 

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There's an awful lot of bad information in this thread.

As a kid, my dad taught me how to make good soldered and crimped wire connections - he was certified to NASA standards for work on the Apollo program. Millions of crimped electrical connections have gone into mission-critical hardware in space. As an adult just out of college, I worked in electronics manufacturing where, among other things, I made thousands of crimped and soldered connections.

A properly crimped connection has appropriate electrical and physical properties and has no more susceptibility to vibration than another type of connection. Soldered connections are more difficult to execute with appropriate physical properties - it's very easy to damage insulation with excess heat or wick solder and flux far from the joint.

The example joint cited by the OP could be completed with a crimp or solder, although most people would have difficulty preventing heat damage and wicking if they soldered the joint. The tech was right to physically reinforce the solder joint.

Glen
 

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I have a (carefully) crimped connection of my cylinder #1 injector. It has developed a "short". I've pulled the connector off a half dozen time and have broken the plastic clip, making it much more likely to come loose again.

I can't find a single injector for sale, much less just the plastic clip on top I need. A set of 4 injectors is over $300, just to let them sit on a shelf forever.

Moral of the story: not sure. As is the basis of this thread, should I have soldered instead of crimping? Looking back now it seems so, but I was concerned about damaging something with my moderate skill with soldering. The crimp did make it fine over 10,000 miles though.
 

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Discussion Starter #11
XHILR8N!I can't find a single injector for sale said:
Clip for which car? I had source 4 used stock clips for the Elise, that's what we were soldering. It took digging, but I found them for free. I payed the guy $20 because it was a Sunday, and he pulled them from his junkyard while on lunch from visiting his dad in the hospital. Sometimes strangers are surprisingly kind...



If these are your injectors, they are also on many Toyotas and Scions. Not surprisingly, cars with 2zz or 1zz engines. A few bucks at a junkyard will find one. Conversely, they are all over the internet new for under $10 each. The most popular aftermarket clips are a GM variety and they are much easier to find.

If it's a different clip, post a picture and description of car/injector. I'd be happy to try to you find a new one.
 

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Discussion Starter #12
This is how the pros do it...
Motorsports ECU Wiring Harness Construction

Every article I've read to date says soldering is bad.
Woah! I'm at work! You didn't mention all the Pin-ups at the end of the article.:rolleyes:

Many of the techniques are money no object, but there is much information in that link. I'm looking forward to studying it.

I've generally heard towards crimping, too. I asked my mechanic's opinion, and he said that he has to repair crimps frequently, but he has never had to repair a quality solder. He has worked in some interesting fields, and built many drag and stockcars. Regardless of the academic discussion, I knew that HIS soldered joints were better than his crimps. I am also realistic that the entire harness was cut and bullet connected at the ECU during the original turbo installation. One day, I'd like a new harness entirely...
 

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You don't solder a connection that is subject to vibration as in a vehicle.
Michael
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Just take a look at the standards for attaching electrical connectors in aircraft. You will not find soldered connections on aircraft unless the wiring is properly supported to eliminate vibration. The wicking action of the solder as it flows into the stranded wire solidifies the wire so the soldered wire will no longer flex and absorb the vibrations transmitted into it. The flexible wire strands will eventually fail after enough vibration at the junction where they meet the solidified soldered strands.
 

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LOL,
I have soldered connections in use, which are probably older than most people in this forum. When dealing with vibrations, double layer heat shrink an inch and a half from the soldered connection, it introduces stiffness in a more gentle fashion further from the stiff soldered point, this makes it to where there isn't a sudden transition from flex of the stranded wire and the stranded wire with solder on it (where it becomes suddenly stiffer). Even stranded wire (which is flexible) will have an abrupt transition to rigidity at the crimped point, with a crimp connector, so you are back to the exact same problem as a soldered wire. As a note, aircraft connectors have a clamping strain relief built into an aircraft rated connector, which should (hopefully) prevent vibration from being translated to the actual physical connection. Some of my soldered connections date back to 1964 (a working model in a museum), so I have a good baseline for my opinions. I have never had to repair a single (properly soldered) connection, with the exception of components which became so hot, they unsoldered themselves (component failure), or where they were subjected to physical forces which ripped them out (typically the wire will break first). I have repaired dozens of crimped connections in my life; I have little faith for good reason. When I installed my HID lights the connections were soldered where possible; I did not use the spade connectors which came with the kit. Even back in the day when I did wire-wrap on prototype circuits, the critical connections were always soldered if the circuit was put in permanent use. If you can't perform a good solder joint, then crimp can always be a plan b.
 
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