Splicing wires

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jedomfl

Active member
Joined
Jun 1, 2012
Messages
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Location
Florida
My Car
72 MACH 1 351 5-SPD YELLOW
Hello Gang,

I'm starting to work on installing a new wiring harness and wanted to know what has worked for others that have taken on this project. What is the best method for splicing new into exiting wires/connectors? Any pics would be great.

 
I solder and tape my connections but they say your not supposed to due to vibration. I also use insulated connectors when I can. In my opinion if it is at all possible to keep factory connections then do it.

 
I rewired the whole car with new wire and soldered then heat shrunk the lot.

On many occasions where I need to use crimp connectors, eg: spade plugs, etc, then I take the plastic off the crimp first, then crimp, solder and heat shrink. On the rare case where vibrations may split a solder, the heat shrink will hold it firmly in place and basically force a connection anyway.

 
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I too have heard of the "rigid joint" solder cracking phenomenon.

I have never, never, EVER, had a failed solder joint on an automotive wire. Over many years of car, truck, boat and bike ownership I have never repaired someone elses failed soldered wire due to "cracking".

Cars from the Flintstone era still have functioning lights and radios... and the radios have glass vacuum tubes in them!! Maybe in an industrial or manufacturing application where repeated amplified bending of the wire would break it, such as a robotic arm, around a hinge area in a doorway, etc... sure.

But for an under hood or under dash application?

I call BS.

An old wives tale at best.

An over-thinkers fantasy come true.

I'll take my chances. In my world, it's solder and heat shrink, amigo. :)

 
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+1 on that.

That story may have originated from soldered connections onto circuitboards which can legitimately become dry solder joints.

EG: In amplifiers, etc, where it goes from hot to cold to hot to cold, etc. I too, in all my years in electronics haven't come across a failed soldered wire connection.

 
I always solder and heatshring,

I tin the wires first, then make a hook shape then connect both hooks and solder them, it seams to be the best way I have found so far.

I rewired my boat 10 years ago and I have not has a problem with solder breaking or the copper oxidizing from moisture yet..

 
These are all I have used for the last 3 years. They are Marine Grade (salt water) solder butt connectors. Right after the solder joint melts you just keep going to the end and it shrinks and seals with goo around the wire. No rust on any of these connections in my other car so far!

DSCN1626.JPG

 
Interesting that everyone so far goes for solder.

That's fine, so long as you're doing a small number of repairs, as each solder joint takes a fair amount of time to set up and accomplish. Most people forget to wash the solder joint in alcohol to remove the flux; if you don't, the joint corrodes over time.

Personally, I use shrink tubing over uninsulated butt splices. It's quick, effective, and economical (I typically have 2-3000 joint repairs per year). If you deal with any of the resistor wires, they will not accept standard solder: you must either crimp them or use silver solder.

This is a classic controversy in the electrical industry: crimp or solder. There are pros and cons on each side and no right answer.

 
I say whatever method works for you is the best way to go. Especially, whichever method does not have you using your teeth as wire strippers. rofl

I've had good luck with plain ol' automotive butt connectors and heat shrink myself. But because I don't ever want to mess with electrical stuff on this car once it's running, I'll be looking into those marine-grade connectors Mark mentioned - those things are slick!

In my experience (and I'm no expert by any means), cold solder joints typically happen as a result of rapid heating and cooling, not as much from vibrations (the wire's usually not under any torsional stress... but the solder also supports the weight of components on circuit boards in addition to making the connections). Most of the component repair I've done involved de-soldering, removing, replacing, and re-soldering small capacitors, resistors, and other components in Digital VT-240 monitors and VT-100 'dumb' terminals as they failed due to heat issues - mostly on high-voltage power supplies and the high-temp areas of the main boards.

If the wires are secured (i.e. not bouncing off the firewall or anything), they should be fine soldered and 'shrunk. I just hate soldering stuff in the car because I usually wind up getting a wire or two crossed during the process and have to tear it all apart again (mostly stereo installations), or forget to slip the shrink tube on before making the splice (Gawd, I can't even remember how many times I've done that).

 
Thanks for the help. Sounds like solder and shrink tube it will be.

 
These are all I have used for the last 3 years. They are Marine Grade (salt water) solder butt connectors. Right after the solder joint melts you just keep going to the end and it shrinks and seals with goo around the wire. No rust on any of these connections in my other car so far!
I have used those and they work GREAT

 
Interesting that everyone so far goes for solder.

That's fine, so long as you're doing a small number of repairs, as each solder joint takes a fair amount of time to set up and accomplish. Most people forget to wash the solder joint in alcohol to remove the flux; if you don't, the joint corrodes over time.

Personally, I use shrink tubing over uninsulated butt splices. It's quick, effective, and economical (I typically have 2-3000 joint repairs per year). If you deal with any of the resistor wires, they will not accept standard solder: you must either crimp them or use silver solder.

This is a classic controversy in the electrical industry: crimp or solder. There are pros and cons on each side and no right answer.
+1 on uninsulated butt splices with heat shrink tubing. This is the best heat shrink tubing I've found. It is self sealing. http://www.heatshrinktubingdirect.com/adhesive_lined_polyolefin_heat_shrink_sleeving_3_to_1.html This method is what ford uses when a splice is required. Chuck

 
I used my daughters used bubble gum to fix a broken wire on my boat trailer as an emergency repair on the side of the road. I forgot about it and rediscovered the repair several years later and the lights were still working fine! But I finally fixed it with the crimp connector and black tape.

 
I wish Ford used insulated crimps and heat shrink. Several years ago Ford had a recall for the cruise control wiring. What they did was cut the power wire to the cruise control and scotchlock a fuse into the line. I was shocked... they did this hack job right in front of me!

 
I wish Ford used insulated crimps and heat shrink. Several years ago Ford had a recall for the cruise control wiring. What they did was cut the power wire to the cruise control and scotchlock a fuse into the line. I was shocked... they did this hack job right in front of me!
Ford doesn't build them like the used to. And in addition to crap like this, they have Microsoft inside.

 
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