Chevelles.com banner

1 - 20 of 43 Posts

·
Premium Member
Joined
·
2,393 Posts
Discussion Starter #1
I have always assumed that a solder connection was better electrically than a crimp. But I just found 2 different (internet - FWIW) references that say a crimp will have lower resistance.
I know that first, a solder joint must have a good mechanical connection, before applying the solder. So which is better in automotive applications.
 

·
Registered
Joined
·
153 Posts
solder joints are always better, I used to work on aircraft and we used solder joints as much as possible. Solder joints hold up better under vibration and moisture. As far as resistance goes, I've never heard that, and if it did Im sure it wouldnt matter in an automobile. I'm sure if you stuck a meter on either joint that you see much if any resistance differance. I'm sure there'll be someone who wants to argue but if it works on 30 year old c-130's its good for me.

Steve
 

·
Registered
Joined
·
153 Posts
Also, most cannon plugs/wire harnesses have solder joints in them connecting each wire to each pin, some are crimp style but most are solder.

Steve
 

·
Registered
Joined
·
1,413 Posts
I've never seen a properly done crimp fail in an automotive application or, for that matter, in an industrial motor application at work. At work we crimp everything from 16 guage control wires to 4/0 power wire and beyond. You have to provide some means of supporting the wire by the insulation or the wire can break off but this applies for crimping or for soldering.

Peter
 

·
Registered
Joined
·
3,091 Posts
I deal with failed crimped connection everyday at work. Our biggest headache is crappy aftermarket wiring causing loose connections and failing.
 

·
Registered
Joined
·
650 Posts
I also vote for solder. Get the butt splices without any insulation on them, tin the wires, insert, crimp if you must, but then solder. Clean off flux to prevent corrsion from acid.

I always put two layers of heat shrink on, one on top of the other, just for extra safety. By the way, there is cheap heat shrink and good stuff. Don't bother with the cheap stuff.
 

·
Registered
Joined
·
1,413 Posts
Originally posted by dennis68:
I deal with failed crimped connection everyday at work. Our biggest headache is crappy aftermarket wiring causing loose connections and failing.
I did say properly crimped connections, not crappily done ones. Using low quality wire will sometimes let the connection corrode but then that's not the fault of the crimp connection. I've seen soldered connections crimp just upstream of the solder. The best wire to use is tinned stranded wire.

Crimping requires a proper crimping tool, not pliers or vice grips. You'd think that was obvious wouldn't you? Use good wire and good crimps and you won't see a problem. If it's outside, you obviously need to seal the connection from the weather. Using heat shrink with the glue inside it is great for this. I don't know any actual names for this but it has stuff that's similar to hot glue on the inside of it that melts into into the connection and seals everything. If not, some type of brush on sealer or sealer in a tube. If you use heatshrink without the glue it will not seal, no matter how good you think is is or what anyone else will tell you. It comes close, but it doesn't completely seal. For use on a nice day low milage car it won't leak enough to fail but on a daily driver in exposed to winter conditions it eventually will fail, maybe even within a couple of years.

It seems odd that crimping is considered so bad, yet every car made has all of it's wiring ends crimped.

Peter
 

·
Registered
Joined
·
87 Posts
I crimp, then solder, and then heat shrink . . . and yes I do believe in belts, suspenders, and stapling the shirt to the pants.
 

·
Registered
Joined
·
846 Posts
Nothing wrong with a proper crip on, but they are ugly if you are putting it where it will be seen.
 

·
Registered
Joined
·
3,091 Posts
Peter, NO CHRYSLER built in the last decade has any crimped wires, this goes for recent built GM's and Ford too. We crimp (only to hold the wire while soldering) and solder every connection in the vehicle, and not with the locally available connetors, they come direct from Molex or Packard in most cases. Every circut in every module is soldered, every center splice is soldered, every pin is soldered.
 

·
Registered
Joined
·
7,762 Posts
Dunno, why would I want to crimp on 30+ year old strained copper when I fight to get it to accept flux.
 

·
Premium Member
Joined
·
2,223 Posts
Either can give a reliable connection if done correctly or either can cause problems if done incorrectly. If I'm using factory type terminals I crimp using a quality crimping tool. When splicing I use a but splice as described by Chevl_Steve, except I use double thick shrink with sealant (available from Hi-Line) This pic shows the crimp tool and the crimp you end up with. The tool along with a Varity of jaws or mandrels, will cost about $100.00. Poor quality crimps are asking for trouble as well as improper soldering techniques. Any one watch the American Hotrod "Junkyard Dawg" when making the positive battery cable the starter end terminal was clamped in a vice, heated with a torch and filled with solder. The cold battery cable was then installed in the terminal, can you say cold solder joint. Guarantee there will be problems with that solder connection in the future, More often than not too much heat and too much solder is used, the solder runs or wicks 1/4" or more up the wire. When the wire is moved it can easily break where the wire meets the terminal.

Use which ever you prefer just do it right and end up with a trouble free connection. Personally I prefer crimp.

I have also personally installed "Pile connectors" multi pin connectors designed for aircraft, the gold plated pins or contacts, as they call them, are crimped on the wire using tools designed specifically for the Pile connector.
 

·
Registered
Joined
·
532 Posts
I have also soldered and applied heat shink tubing to my automotive electrical connections. I would not do anything else on these 30 year old cars!
 

·
Premium Member
Joined
·
2,173 Posts
Clean off flux to prevent corrsion from acid
Folks, NEVER but NEVER use acid core solder on electrical connections. Don't us acid flux on electrical connections either. Acid flux is strictly for plumbing and mechanical soldering. Using an acid core solder or acid flux on an electrical connection will cause corrosion and deterioration of the wire and/or connector over time (and a short one at that)!! Go look at the plumbing joints in your house. See the white and green corrosion near the joints? That's what acid does. It'll do that to your connections too, then travel up inside the wire insulation and eat up the wire.

A non-acid flux will not cause corrosion. It actually prevents it. Electrical solder (and flux) is actually made from rosin and other products. It is non-corrosive. If you can't get a wire to tin with electrical flux, use a 400+ grit paper to "sand" the wire to expose raw, fresh copper. If it stil doesn't tin, replace it but NEVER use an acid product.

(and yes, I've actually been to school on it and I have a Certification in soldering from NASA)
 

·
Premium Member
Joined
·
6,741 Posts
Good point Herb. I don't remember the last time I saw acid core solder, of course I haven't looked. I just 'borrow' rosin core solder from work. Someday I'll have to round it all up and return it I guess.
 

·
Registered
Joined
·
7,762 Posts
Originally posted by Herb:
A non-acid flux will not cause corrosion. It actually prevents it. Electrical solder (and flux) is actually made from rosin and other products. It is non-corrosive.
Extremely boring stuff but some rosin flux is slightly active. Don’t click if you need a nap. A lot of manufacturing companies conform to the J-STD. The conditions under a hood (heat and moisture) are ideal to promote corrosion. At home it is better to clean the joints with isopropyl alcohol but I rarely to that. I'm too lazy and for car wiring the stuff in the links don't mean much. Just seeing if Herb will fall asleep reading it.

www.alphametals.com/products/techarticle/1999120034.pdf
http://www.smtinfo.net/docs/Whiteres.html
http://www.necel.com/pkg/en/mount/2/2_3/
 
1 - 20 of 43 Posts
Top