What technique are you using to splice the wires in the
harness on an engine swap?

I've tried to push the ends of the wires together and soldering
them to keep the joint small enough to slip heat shrink tubing
over the joint. But I don't get the clean/tight solder connecion I want.

I use a solder gun and/or a 25 watt soldering iron and electronic
grade rosin core solder.

I could use crimp connectors but that can get kind of "lumpy"
when I try to put the wires back into a loom.

Ideas??

The splice you need is the "western union"...
start by bending the two wires in to a L shape about 3/4 down the striped end... _/ \_
hook the two wires together... _\/_
twist the end one wire onto the other... repeat for the other wire... ---oooxooo---
solder the joint...
it will be the same thickness as the casing of the wires and will make a smooth, strong splice...

hope this helps
Chuck

Same as above
Western-Union Splice
http://www.mmxpress.com/technical/connections.htm
http://www.saskschools.ca/curr_content/paasurvey/elec/lesson5/lesson5.html

[This message has been edited by Jake_Dragon (edited 10-08-2005).]

I do basically the same type but I dabb the ends with flux before I solder. I find I get instant bond that way.

Arn

Get a bigger soldering iron/gun. I use a Weller induction gun for common wire work. It heats and cools fast. It makes allot of heat and concentrates it into the joint fast. If you use a gun properly you make better joints faster and with less damage to the insulation on the wire.

You also need to stagger the splices. Even if you make clean joints the thickness of the shrink wrap alone needs to be sread out so you don't end up with all the splices in one spot.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurasic Park)

The Ogre's Fiero Cave (It's also at the top of every forum page...)

I solder everything I splice and then cover with heat shrink tubing.. I hate crimp connectors..

As Ogre says.. get a hotter iron.. (I normally use a soldering gun).. Tin the wire ends first.. (Melt a small amount of solder on the wire tips.. Just enough to get them silver.). Then when you solder them, you should get a clean tight connection...

I had some problems before of this type, I then started using *Silver Solder* ...it made a world of difference, it cost a little more, but worked better..........hope this helps some.....

Silver Solder melts at a higher temp but is stronger than regular 60/40 solder. Always invest in flux. It's cheap and solves alot of headaches even if the solder is flux cored. I also recommend cleaning any flux residue off as this will promote corrosion. Isopropyl Alcohol (HEET in the red bottle) works ok but there are better flux removers available.

...heat the wire with the soldering iron/gun, when hot apply the solder to the wire only (not to the iron/gun). If the wire is at the correct temp, it will melt the solder and allow it to flow into the strands of the wire. You never apply the solder to the heat source as it will stay on the surface.

Heat of the iron/gun depends on the guage of wire you are trying to solder. "Most" wire (the 18-24 guage wires - ie dash wiring) in the car can be soldered just fine with a 35 watt iron/gun. The large wires (16-10 guages - ie purple starter wire) you will need a larger iron/gun, 50 watts should do.

I start by stripping off about 3/4" (larger gauge wires you need to strip more off):

cross the wires at the midway point:

wrap one end around the other wire:

[This message has been edited by Mickey_Moose (edited 10-09-2005).]

good stuff - everything above
something that helps with smaller soldering irons: solder on a peice of wood, like a small peice of 2x4 - as in lay your work on the board, and hold it down with the soldering iron. this will help save your heat. if your have the work against metal, it will just suck up all your heat. also, solder doesnt stick to wood/paper.

I find dipping ends in flux works a little better than tinning, makes it easier to twist then together, and the flux makes then suck up the solder REAL quick.

also, I have used the "cold heat" things. they do work, but takes some finagling.

shrink wrap is good, but if you must tape, ties straps are good for keeping them from unwraping - and of course - you can use both

Tightly wrapping electrical tape completely over the solder helps from bending and looks just as pretty as a wire loom if its wrapped tight. =)

Electrical tape often doesn't hold up well in an engine bay. Even the best tape usually ends up falling off after awhile. Shrink tube is pretty easy to come by these days. Cheap to if you shop around.

You can also use self vulcanizing tape but it's thicker than heat shrink or electrical tape so it will make splices bulk up fast.

Thanks for all the great info! I'm down to the wiring harness hook-up
on my 4.9 swap and will make use of the ideas here.

Bob

quote Originally posted by Pyrthian: I find dipping ends in flux works a little better than tinning, makes it easier to twist then together, and the flux makes then suck up the solder REAL quick.

I never tin or used flux in any of my soldering (been soldering for the last 20 years) - just use 60/40 rosin core solder and as long as the heat is correct there should be no problems. The only problems you may have is if the wire is old and oxidized, but you can clean the stands up with a brass brush if they are really bad.

Always use heat shrink, the only exception is if you don't cut the wire - as it's kind of hard to add heat shrink in this case

If splicing is out in the enviroment (engine bay, etc), use heat shrink that is weather proof. It is made up of 2 sleeves and has a glue inside to seal off the ends when shrunk to keep water/etc out.

quote Originally posted by Mickey_Moose:

[Dire Straits] That's the way you do it! [/Dire Straits]

Everybody said it all but I'm in theogre corner about cutting the wires on an angle. When converting my 86 headlights to 87-88 style I went to the boneyard but forgot to take the right sockets to get the rad out of the way. I know somebody out there is gona shoot me but I had no choice but to "politely" cut the harness (while no one was looking) near the end on the pass side. Anyway I cut the harness wires on a steep angle so there would'nt be a large lump after splicing.
Another benefit is you can match the wires up better when there all not cut the same length and my luck would be seeing 3 brown wires in the bunch all looking the same shade. I know you've been there...is it brown or is it black?????

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I picked up on this trick while working in marine research.

Any time you solder, you are putting two disimiler metals (wire-solder) together. Over time there will be some galvanic reaction (corosion), especialy where water is involved. I have seen many joints fail, usualy due to moisture and vibration ( the soldered joint is less flexible than stranded wire). Heat shrink really works good to protect a solder joint mechanicaly, and electricaly from short circuits. However in harsh conditions sometimes water can wick up between the heat shrink and the insulation due to capillary action. I've found solder joints that have gone bad due to corosion, even when the heat shrink looked OK.

For splices outside of pasenger compartment, I sometimes go one step further than Heat Shrink alone. I spread silicone grease over the soldered joint, then slide the heat shrink back over the splice. Make sure the heat shrink is long enough to make a good mechanical anchor over the insulation on both sides of the joint. Heat the shrink from center out. Most excess grease will squeaze out the ends, some may actualy be squeazed between the wire and insulation, the object is to displace the air out of the joint.

The point is that air expands and contracts, this may suck water up into the joint, grease won't expand or contract significantly, and will keep water from invaiding the splice.

At work we "float tested" some equipment that went 'negatively boyant'. It took a couple of days to recover the equipment from 150 ft of salt water, but the wiring was solid, and lasted for over a year till we upgraded to newer equipment.