What solder to use on basic automotive wiring?

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dibbons

dibbons

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I would like to do some wire repairs using soldered connections instead of the crimp connections that (for me) often fall out no matter how hard I crimp. What is the best type/mix/ratio solder? My past experience soldering wires were not much better than the failed crimps.
 
If I recall, any ROSIN core 90/10 or 80/20 will work fine. Do yourself a favor and invest in soldering paste as well.
-Matt
 
60/40 mix leaded solder is best, followed by 50/50 leaded, followed by 60/40 lead free. The lead free requires a bit higher temperature, but most irons can manage that. Don't even think of using plumbing solder; use only solders for electrical connections.

Clean your connections thoroughly with alcohol after soldering to get all the residual flux out; flux absorbs moisture and corrodes anything metal around it. And minimize how far that the solder wicks up into the wires; if that happens, the stiffened, solder-filled wires will have a tendency to break off just outside the connector with long-term vibrations.
 
60/40 used to be the "accepted" ratio. make sure it specifies on the box for electrical and ROSIN core and not acid core

actually radio shack solder if still open, is OK. I heard they are goin out

one thing you can do is use the above pliers. i think betts and klein make em. use bare uninsulated crimp splices and solder them after crimping then put a short sleeve of heat shrink. you can buy less pricy heat shrink from people like moser electronics in like, 4 ft lengths.
 
At work we used the 80/20 solder and it worked well.

Also if you are using crimps especially where outside elements play a factor I use heat sealing crimps and as Daves69 said use a really good pair of pliers.
 
Daves69 said:
Maybe invest in better crimps? I've used these forever it seems. Never had an issue with pull out of solder less connectors.

http://www.grainger.com/product/STA...m/rp/s/is/image/Grainger/3KH45_AS01?$smthumb$
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I have a pair exactly like that; it is a great crimper. You can find crimpers like that at places like Lowes but the quality in the jaw alignment is variable; you have to be picky on which one you actually buy. Also make sure to align the crimper jaws so that the 'nub' that pushes into the crimp sleeve is always on the opposite side from the split in the crimp sleeve.
 
And 60/40 melts at the lowest temp. (63/37 actually....) Nothing in car wiring gets even close to where the solder will melt, unlike other apps where high temps exist. Perhaps soldering the stator winding leads to the diodes in a high output alternator or inside a starter might be a smart place for 80/20 or 90/10.
 
nm9stheham said:
And 60/40 melts at the lowest temp. (63/37 actually....) Nothing in car wiring gets even close to where the solder will melt, unlike other apps where high temps exist. Perhaps soldering the stator winding leads to the diodes in a high output alternator or inside a starter might be a smart place for 80/20 or 90/10.
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I prefer 50/50 wire solder, it`s half lead and melts at a lower point than 60/40, which is good also. use plain roll solder w/ a good "non acid" elec. flux no problem w/ crimp conn. either
 
If you MUST crimp, get the ones that you heat and they shrink down and spooge out a bunch of sealant. No corrosion and additional mechanical security.

They cost a lot comparatively, but there's no competition.
 
nm9stheham said:
I have a pair exactly like that; it is a great crimper. You can find crimpers like that at places like Lowes but the quality in the jaw alignment is variable; you have to be picky on which one you actually buy. Also make sure to align the crimper jaws so that the 'nub' that pushes into the crimp sleeve is always on the opposite side from the split in the crimp sleeve.
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crimp.jpg
 
Make sure you're not using the cheap crimp connectors that are hard plastic, those never seem to bite onto the wire correctly.
 
Take a good look at post #2 and #12.. Those are the type of pliers you need to use , and how to use them, if you want guaranteed results. The el-cheapo crimping pliers that often fail are pictured below.

As far as soldering your wire connections, I would advise against it. Use some good terminals and a decent set of crimpers and you'll have great results! Soldered connections, as far as I know, are not used in any vehicle from the factory. That goes for RV's as well.
 

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60/40 rosin core is mil spec. Just remember to wipe the extra flux off with alcohol when finished to prevent corrosion.
 
bighammer said:
As far as soldering your wire connections, I would advise against it. Use some good terminals and a decent set of crimpers and you'll have great results! Soldered connections, as far as I know, are not used in any vehicle from the factory. That goes for RV's as well.
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I stopped soldering connectors in my race cars after a few broke off right outside of the connector; as noted, the solder will tend to wick out into the wire strands, and create a stiff area right there near the end of the wicked solder. All the weight of the wire under vibration will concentrate there and tend to anneal over a period of time, and then break. If you do solder, then it is wise to make sure the wires are well supported a few inches beyond the solder point.
 
nm9stheham said:
I stopped soldering connectors in my race cars after a few broke off right outside of the connector; as noted, the solder will tend to wick out into the wire strands, and create a stiff area right there near the end of the wicked solder. All the weight of the wire under vibration will concentrate there and tend to anneal over a period of time, and then break. If you do solder, then it is wise to make sure the wires are well supported a few inches beyond the solder point.
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That's not annealing, That's work hardening
 
I have the crimpers in post #2, for spade terminals (fork or ring), and for "butt crimps" if I were to use them (not). For the "56 terminals" in most Mopar connectors (new), I use smaller crimpers that fold the sides around in tight semi-circles like the factory did. I found those at Fry's Electronics for ~$18. I usually solder after crimping, since it makes me feel good, though many say you don't need to and/or shouldn't. To connect 2 bare wires, I use solder w/ heat shrink.

The solder should flow into the wire itself. Heat the wire and let the wire melt the solder and wick it in. Don't touch the iron to the solder and try to drip it onto the wire. Your iron tip should stay "tinned". Periodically wipe it on a wet sponge and re-coat w/ solder to give better heat transfer. You must have flux-core solder, or even better separate flux (rosin), and wait until the flux is bubbling. You can clean the flux w/ soap & water or citric cleaners.
 
FRY'S I MISS THAT PLACE. To all that do not know about it's a Radio Shack on steroids. Never saw them except in California.
 
bighammer said:
As far as soldering your wire connections, I would advise against it. Use some good terminals and a decent set of crimpers and you'll have great results! Soldered connections, as far as I know, are not used in any vehicle from the factory. That goes for RV's as well.
Click to expand...

The Blue Bird Bus has soldered connections factory. It has been years since I have done cars so I cant quote those but 20 years ago Ford Prototype we soldered our connections.
 
bighammer said:
As far as soldering your wire connections, I would advise against it. Use some good terminals and a decent set of crimpers and you'll have great results! Soldered connections, as far as I know, are not used in any vehicle from the factory. That goes for RV's as well.
Click to expand...

i have been trying to figure out without success why someone would say this .
 
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