Crimping / Elect Connections - How To

[Wavery]

Originally Posted by scrubjaysnest

nice drawing Bill, I have found the same to be true plus the crimp lugs tend to be tool specific. AMP makes crimps lugs and tools that work well together but price is up there. Generic and soldering has always worked well for me, more time then money

I don't really see the value in using a crimp and soldering. I guess it is smoother than twisting and soldering but if one is using heat shrink over properly twisted wires it makes a good, clean connection that is well insulated.

[mjlaupp]

FWIW
I found this thread on SailNet:
http://www.sailnet.com/forums/gear-m...nnections.html

[HIKERZ]

Depending on the size I tend to use gel splices - either the inline (smaller awg) or wrap around for larger -- cost a little more but then I am lazier than I am cheap

[Bill]

Wayne -

The purpose of soldering (after performing a "squish crimp") is to fill the empty space left in the barrel of the crimp. Otherwise, one or more individual strands of the wire can migrate into a void, which releases the pressure on the other strands, instantly destroying the integrity of the crimp. The "wedge crimp", with a proper ratcheting tool, does not leave any voids, so this problem does not occur. That's why your car has hundreds of wedge-crimps, many not covered with any protection at all.

If you use a squish-crimp, and you don't solder, at the very least you should pull firmly on the wire after the crimp is made. In my experience, the wire will pull out of the crimp an unnerving number of times.
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Mike -

That's a good discussion from SailNet. One of the discussion questions is whether soldering makes the wire stiff or rigid, making it more prone to breakage if the wire flexes at the end of the soldered portion. It certainly does - but on the other hand, even if it is not soldered, a (flexible) wire entering an (inflexible) connector barrel will fail if allowed to flex at the joint. It is my feeling that a relatively long piece of heat-shrink tubing is a good start toward immobilizing the joint, but the overall answer, as the discussion concludes, is to support the wire in such a way that no flexing can happen at the joint.

And of course, use electronic solder, not plumbing solder. The SailNet participants seemed to have some confusion about this. Plumbing solder has an acid flux, which will corrode copper wires. Electronic solder contains a rosin flux, which does NOT clean the wire, does NOT attack copper, but converts copper oxides back to metallic copper.

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An example of a proper wedge-crimp tool can be seen here. It is a Delphi tool (Delphi is a big supplier to carmakers) and it costs $80. You can see the wedge in the jaw of the thing. Wish I had one. Guys who seriously restore classic cars own them, and won't use anything else.

Bill

[Wavery]

Originally Posted by Bill

Wayne -

The purpose of soldering (after performing a "squish crimp") is to fill the empty space left in the barrel of the crimp. Otherwise, one or more individual strands of the wire can migrate into a void, which releases the pressure on the other strands, instantly destroying the integrity of the crimp. The "wedge crimp", with a proper ratcheting tool, does not leave any voids, so this problem does not occur. That's why your car has hundreds of wedge-crimps, many not covered with any protection at all.

If you use a squish-crimp, and you don't solder, at the very least you should pull firmly on the wire after the crimp is made. In my experience, the wire will pull out of the crimp an unnerving number of times.

Bill

I guess I wasn't very clear on my point.......

I understand the value of soldering when using the crimp. If you are going to solder anyway, why use the crimp at all? I don't see the value.

The 3M heat-shrink connectors have a low temp "Solder" (it's really a conductive cement) that fills the gaps and the heat-shrink adheres to the wire's insulation. To me, that's the next best thing to soldering. I have a full selection of those things and I use them in most applications. Just not on the brake wires. Those get solder and heat-shrink.

[scrubjaysnest]

Originally Posted by harveyrv

I guess I wasn't very clear on my point.......

I understand the value of soldering when using the crimp. If you are going to solder anyway, why use the crimp at all? I don't see the value.

................snip.............

Wayne
Have you ever tried twisting anything larger then #10 ? Even with linemens pliers I have never been able to get the twist to hold long enough to solder it. I just got in the habit years ago with using butt splices then solder.

[Wavery]

Originally Posted by scrubjaysnest

Wayne
Have you ever tried twisting anything larger then #10 ? Even with linemens pliers I have never been able to get the twist to hold long enough to solder it. I just got in the habit years ago with using butt splices then solder.

Good point .....even 10G is hard to twist. I can see soldering butt connectors or end terminals in that case. I guess I was just thinking of the brake wires.

[Bill]

Wayne -

You are right. To make a butt splice (two wires end-to-end), a twist-and-solder approach is a perfectly good one (in my opinion). Without thinking, I put butt splices in the same category as crimped terminal connectors - ring tongues, forks, spades, etc - where I will crimp and solder every time.

Good clarification - thanks.

Bill

As I have not done much wiring I was gonna ask for a picture of a butt connector or butt splicing to get a better understanding of what they are and the discussion here, but since my request might be taken the worng way, I'll google the terms instead...thanks for the good discussion.

As posted before, I ordered a new Tekonsha P3 brake controller from eTrailer with very satisfactory results in order and delivery. After reading the excellent instructions and comments here on crimping, I am happy with the installation – it seems to work as it should but I have to go to storage to do the final testing with the TM attached to the TV.

I did buy one new tool – a somewhat good crimping tool - but it worked with good strong dimples!. I confess that in the past I have been guilty of just using twisted wire connectors (caps) and electrical tape. I still haven’t found my old soldering iron – haven’t seen it in over 30 years – but will either find it or buy something new before I tackle the brake’s electrical wiring. Not a shade tree mechanic in any sense; so, I always need lots of advice!

Thanks everyone!

Moaboy - Butt connectors are not hard to find locally, but here is a picture:

http://www.amazon.com/Electrical-Wir.../dp/B0002ZPGIY