calling all wiring gurus

[cwapface]

For the longest time, whenever I had wiring to do on a car I would use crimp-on spade or ring connectors without solder. It worked well and was fast and cheap. When I got my mkiii, I wired up the new stereo harness with hook and loop soldered connections wrapped tightly in electrical tape. I think it is assumed that this is the better way to wire things in a car. But when I did my foglight rewire, I couldn't get in there with a soldering iron so I used wiring cap connectors to splice wires. Now for the quiz...

1) Which method is best for low-current wiring? (no HIDs or battery relocation)

2) Which is the worst for conductivity and why? My friend says that crimp connections are the worst thing you can do to a car because they add so much resistance, is that true?

3) What is the best type of connection for wiring in sensitive devices like an emanage or an AEM EMS and why?

thanks for the help, and if you have any helpful links I would love to see them, google hasn't been too nice to me today

 

[shaeff]

at radio shack they have a little butane powered soldering iron. get it. you can reach almost anything with it, and its portable, doesnt use electricity, and comes with a blow torch attachment.

now for my answer, and this is my opinion:

personally, i solder everything. i hate electric tape, so i use heat shrink wrap. i do this on everything i wire that i know isn't going to be taken out. examples: SAFC, stereo, foglight rewire, shorted out wire in tail lights, etc...

try this, if you have the time to do so. get four pieces of wire, equal lengths. take two and connect them using solder, and take the other two and connect them using crimp connectors.

grab a multimeter and measure the resistance of the two, and you'll have your answer. my guess is that it wont be TOO different...

-shaeff

Super late edit, six years later, actually: I've since changed my wiring technique. Proper crimping is best, I no longer solder.

 

[figgie]

logic excercise.

what does solder contain? Tin

a crimp is usually made of? Copper.

Tin + copper equal dissimiliar metals.

Copper + copper = similiar there IS a reason why in the airplane world. One CAN NOT solder wires. They have to be crimped to repair them. Thi is in use by the FAA AND the US Military.

 

[Justin]

interesting ^



i would imagine the resistance of a crimp terminal is under an ohm

maybe more, but i doubt it *shrug*



Personally, I solder everything I can reach, ESPECIALLY stuff when i'm working on the ECU

 

[Idealsupra]

logic excercise.

what does solder contain? Tin

a crimp is usually made of? Copper.

Tin + copper equal dissimiliar metals.

Copper + copper = similiar there IS a reason why in the airplane world. One CAN NOT solder wires. They have to be crimped to repair them. Thi is in use by the FAA AND the US Military.

is it just me or are the harness wires in the car NOT copper? maybe im just imaginging things....

to ME...solder is ALWAYS THE BEST option...

 

[Jetfixr757]

I have to agree with Figgie, we only solder on CERTAIN pinned connectors on aircraft, everything else is crimped, and you are only allowed a certain amount of crimps in certain areas if that is exceeded you have to change the entire run of wire. I personally use aviation style crimps and heat shrink tubing. NO black tape. Over time and heat it will unwrap and cause you problems.
William 89T

 

[bluemax]

I'd solder the wires. The problem with crimp connectors is conductivity. They don't flow current through the connector as well because less surface area of the connector is in contact with wire the stands. I wouldn't worry about dissimilar material. You're not going to have your car that long to make a difference. Also, on corrosion, the crimp connectors don't seal well so you can still get corrosion or oxidation. I've had problems on an automitive butt splice connector before, some oxide or something on the inside of the connector. I had to replace the connector after about 10 years. And if you've used automotive crimp connectors, you'll find out that they don't take too much force to pull the wire out. The aerospace butt connectors are of a different design, you probably can't find them or afford them.
If you really want the best connection, use silver solder. It is the best of all connections. They use silver solder in audiopbile circuit manufacturing where people spend thousands of dollars on just one component interconnect wire. But you really don't need it.
On my stereo installs I've used solder, automotive butt connectors and aerospace butt connectors. My experience is that the solder with heat shrink sleeving is the best for electrical connections. They seem to last the longest, but they are also much more work to install.

I think most wires are copper. Its usually cheap and has good conductivity. The wires probably don't appear to be red copper, but silver in color, because the strands are coated with guess what? Tin. With tin coated on the surface of copper wire for increasing solderability and protecting copper conductors from corrosion in the operation of PVC or Rubber insulated extrusion and prevent insulated Rubber from aging.

 

[figgie]

I'd solder the wires. The problem with crimp connectors is conductivity. They don't flow current through the connector as well because less surface area of the connector is in contact with wire the stands. I wouldn't worry about dissimilar material. You're not going to have your car that long to make a difference. Also, on corrosion, the crimp connectors don't seal well so you can still get corrosion or oxidation. I've had problems on an automitive butt splice connector before, some oxide or something on the inside of the connector. I had to replace the connector after about 10 years. And if you've used automotive crimp connectors, you'll find out that they don't take too much force to pull the wire out. The aerospace butt connectors are of a different design, you probably can't find them or afford them.
If you really want the best connection, use silver solder. It is the best of all connections. They use silver solder in audiopbile circuit manufacturing where people spend thousands of dollars on just one component interconnect wire. But you really don't need it.
On my stereo installs I've used solder, automotive butt connectors and aerospace butt connectors. My experience is that the solder with heat shrink sleeving is the best for electrical connections. They seem to last the longest, but they are also much more work to install.

I think most wires are copper. Its usually cheap and has good conductivity. The wires probably don't appear to be red copper, but silver in color, because the strands are coated with guess what? Tin. With tin coated on the surface of copper wire for increasing solderability and protecting copper conductors from corrosion in the operation of PVC or Rubber insulated extrusion and prevent insulated Rubber from aging.

Oh hell no. we are not going to bring in "idiotphiles" to this conversation. Hell no.
Let analyse you logic. Silver is a better conductor than copper.. so that 1mm of silver solder (which mind you is not really silver. It is 96% tin and 4% silver)will do what again?? oh that right NOTHING. All solder/crimping wire is supposed to do is make a connection of least possible resistance. 4% silver will NOT drop the resistance oF TIN by that much

Again if soldering IS so supperior WHy in the world doesn't the AVIATION industry use it where so many lives depend on that one stupid little connection? Simple solder FAILS in a stressed environment. Cold solder joints, incomplete penetration, etc. Crimping on the other hand does not. And you are aware that the surface area of said crimp can pass about 10X more CURRENT than the wire itself can.. RIGHT?? Copper oxidation is on the SURFACE. At the voltage we are dealing in cars guess what. Besides it looking ugly it does NOT matter one iota.

Please do not ever compare real science to that shit of audiophile nonsense.

 

[Idealsupra]

Oh hell no. we are not going to bring in "idiotphiles" to this conversation. Hell no.
Let analyse you logic. Silver is a better conductor than copper.. so that 1mm of silver solder (which mind you is not really silver. It is 96% tin and 4% silver)will do what again?? oh that right NOTHING. All solder/crimping wire is supposed to do is make a connection of least possible resistance. 4% silver will NOT drop the resistance oF TIN by that much

Again if soldering IS so supperior WHy in the world doesn't the AVIATION industry use it where so many lives depend on that one stupid little connection? Simple solder FAILS in a stressed environment. Cold solder joints, incomplete penetration, etc. Crimping on the other hand does not. And you are aware that the surface area of said crimp can pass about 10X more CURRENT than the wire itself can.. RIGHT?? Copper oxidation is on the SURFACE. At the voltage we are dealing in cars guess what. Besides it looking ugly it does NOT matter one iota.

Please do not ever compare real science to that shit of audiophile nonsense.

figgie in the sense of having an intelligent conversation...

i ask this... is it possible aviation requires crimping because they have MUCH better cimp connectors then would ever be available to the common cnosumer..AND the fact that as you said...soldering can be dnoe wrong in NUMEROUS ways so instead of having to train each mechanic to solder basically PERFECTLY as where crimp connectors are consistent?

i think the best option for your at home mechanic and whatnot is solder...simply because the crimp connectors available to us dont hold like the aviatio ones im sure....

either way let the discussion continue as im learning stuff

 

[bigaaron]

I'm with Figgie too. A good crimp is better then solder for wire to wire connections. Usually when crimps fail it is from crimping on the seam or using the wrong size connector or tool. I did car audio/video/alarm install for 6 years and never had a car come back with a bad crimp connection that I made. Crimped connections have lower resistance and the wire near the joint stays flexable, that is why they are used in aircraft. Crimped connections don't fatigue as quickly as solder. Use good 3M seamless butt connectors. Don't use t-taps. Seamless butt connectors and ring terminals are available at any good electronics store. You don't need a aircraft grade connector to make a connection that is better then solder. I am a manager at Orvac Electronics (orvacelectronics.com), a 30,000 square foot industrial and consumer electronics store. Let me know if you need any connectors and I can hook a nice supra discount. A normal multimeter has a resolution of .1 ohm. You need to go down to about .001 ohm to see the difference. Solder is not bad, just not as good as crimped for a vehicle. The difference is VERY minimal so use the method you are comfortable with.

(Hey idealsupra, we don't agree about anything huh? It's all good bro, you are cool with me.)

 

[bluemax]

Figgie,
I think you're right about the silver content in the silver solder. I don't think it'll melt using a soldering iron if it were pure silver. But there are pure silver cables. The most current will pass through the joint with the least resistance. The resistance will be lower with more surface contact between each conductor and the splicing material. In the case of a mechanical butt connector, the maximum contact is the inner surface of the butt connector with the outer surface of the outer strands of wire. In the case of solder, the solder will fill some of the cavities between the outer strands making more surface contact with the wire.

I've never had a problem with a solder splice. On the other hand, I've had problems with mechanical butt splices on my stereo.

Here check out NASA's view on solder connections:
http://workmanship.nasa.gov/guidadv_recmeth_lapsplice.jsp

 

[Idealsupra]

(Hey idealsupra, we don't agree about anything huh? It's all good bro, you are cool with me.)

hey thats why there are apples and oranges all good here too...

what fun would it be in learning things if there werent differences in opinions?

 

[90T04]

I wouldn't use crimp connectors on any connections outside where they will be exposed to the elements. Inside, like for your stereo and other wiring they work fine. The key would be making sure you make a good crimp with a good quality butt connector and crimp tool. (Scotch-loks on the other hand, are the devil.)

They make these really cool butt connectors that are like a regular butt connector but the insulation part of them is actually shrink tubing. They also have a little bit of glue on the inside of the shrink tubing so that when you heat them it shrinks the insulation and also melts the glue so you have a nice weatherproof connection.

I'm a Workhorse chassis certified technician (RV's) and they only allow us to use those types of butt connectors for exterior wiring repairs except for O2 sensor wiring. (Dont ask why.)

Ryan
Tucson

 

[NATAN666]

logic excercise.

what does solder contain? Tin

a crimp is usually made of? Copper.

Tin + copper equal dissimiliar metals.

Copper + copper = similiar there IS a reason why in the airplane world. One CAN NOT solder wires. They have to be crimped to repair them. Thi is in use by the FAA AND the US Military.

i was goin to mention this... not even for repairs, but my dad is building small single-engine airplane with a suburau boxer engine and the wiring for the ECU had to be custom made with crimps, no soldering allowed.

 

[NATAN666]

and also this nonsense that aeromotive crimps are expensive or rare... thats just you makign things up.. they are cheap and not hard to acquire.. and they do such a great job.. one day im going to crimp to piece of wire together and measure the force required to break the connection.. i know for a FACT that it will be harder than breakign a soldering joint as ive done extensive work using both solder and crimps.

 

[bigaaron]

90t04, that is a good point! 02 sensor wiring is high temp silicone jacketed and regular connectors might melt. Another point, almost every factory wire on your supra has a crimped connection on the end and any wire to wire connections are crimped and shrink wrapped. Same thing goes for every car on the road.

 

[figgie]

In the air force we are taught how to solder a perfect connection. But for airplanes they are NOT allowed in any way shape or form in the wiring. Now on the cannon plug ends dealing with RF frequency they MIGHT let us use it for secuing the wire to the pin itself. Other than that. no way.

BTW those silver wires might have less resistance but their cost outweigh the physical gains. Think LOGICALLY not emotionally. Why would the people that PRODUCE energy (the light companies) still use steel center conductors with copper out shells for transferring electricity from power plants to your home? Simple. Copper is great at what it does and that is transferring energy. A 12 gauge 99.99% copper cable is about the same as a 13 gauge 99.995% silver cable resistance wise.

 

[figgie]

figgie in the sense of having an intelligent conversation...

i ask this... is it possible aviation requires crimping because they have MUCH better cimp connectors then would ever be available to the common cnosumer..AND the fact that as you said...soldering can be dnoe wrong in NUMEROUS ways so instead of having to train each mechanic to solder basically PERFECTLY as where crimp connectors are consistent?

i think the best option for your at home mechanic and whatnot is solder...simply because the crimp connectors available to us dont hold like the aviatio ones im sure....

either way let the discussion continue as im learning stuff

nah

the butt connectors are nothing special. Neither are the tools. Basic rachting crimper is what we used.

Now don't get me wrong. Do what you feel is more comfortable to fix wiring in the car. I am just pointing out the whys of crimp over solder

 

[cwapface]

It doesn't surprise me that the Air Force would require super-strict rules about how to connect 2 wires together. But depending on what plane you are working on, that connection is going to go through a hell of a lot more physical stress and rapid temperature change than a connection on a car.

Regardless, I take it crimping is not a bad way to go?

 

[figgie]

It doesn't surprise me that the Air Force would require super-strict rules about how to connect 2 wires together. But depending on what plane you are working on, that connection is going to go through a hell of a lot more physical stress and rapid temperature change than a connection on a car.

Regardless, I take it crimping is not a bad way to go?

funny thing it is not the Air Force reg. It is an FAA reg. The Air Force follows laws also