Hi guys,

Quick one, what's the best connection method to use in a wiring loom when you are going to splice wires together? Crimp, solder or other?

I am going to install an aftermarket ECU in the car and splice it into the existing wiring loom.

I've had some of the sparkies at work tell me to crimp because solder may cause the wires to physically fail. I've had others tell me to solder because it's cleaner, neater and more effective than crimping, and as long as you secure the loom properly, the wires should be fine.

I tried soldering once before when working under the bonnet, and I found that the solder I had didnt really want to take to the wires. Any advice on which type of solder to use if I do solder it together?

Comments?

Cheers,
Nic

I'm not an auto electrician but I've soldered quite a few wires over the years. To use the crimp method, I gather you'll be cutting the wires & rejoining. You can solder the ends of the wires to spade connectors. With splicing, I found that electrical tape comes apart after a while due heat. That can be the cause of wiring shorting out. Not sure if there's any heatshrink you can wrap around spliced wiring.

If you use some flux and a large (80w) soldering iron, you can get a lot of heat on the joint/connection in short amount of time. I use a damp sponge to remove any flux residue. Some wires seem to have a coating that resists solder, but all the ones I found in Fords are easy enough to solder. Clean the soldering iron tip regularly and keep it free of flux residue.

resin (flux) cored solder is a must... It allows the solder to take to the copper and it would not really take if you didn't have flux...

When soldering wires a double flat iron of 40W or bigger is ideal...

I find that crimps cause issues when people try to crimp too smaller a wire with too big of a lug... And also when they use one of those cheap 10 dollar crimping tools...

All the 35mm Anderson plugs in my car I soldered... This requires an oxy to do as opposed to a iron... And lots of solder (big diameter stuff)... Advantages are that corrosion cannot occur and dirt cannot become trapped (as what happens with crimped joints)... Stronger joint and cannot fatigue at the weak spot as the solder will travel back up inside the insulation and make the whole thing stiff...

My preference is always soldering... But you get to a size where it is not feasible and fatigue isn't an issue when you're dealing with cables from 10mm squared and up...

What about aerpro's adaptors?



This is for EF?

You get these, solder it to your headunit harness out of the car... plug one end into you dash harness... other into your headunit...

Costs under $20 buck and I will never fit a headunit without one... Quicker, easiest and instantly reversible...

http://www.aerpro.com.au

Cheers,
Tim

Nicco is actually installing an aftermarket ECU Tim not a headdeck.
I am a voter for solder. Use a good iron and quality solder , make sure everything is clean and insulate it well.
After all Ford themselves soldered the wires splices in their factory looms.

Sorry, maybe I need to clarify my original post.

As I said originally, it's an ECU that I am putting in.

I will be running it stand alone, and joining the loom from the EMS to the loom already in the car.

If I crimp it, I will be using these:


*edit: Thanks Evl. Posted while I was typing.

Thinking about it though, not a bad idea using an intermediate plug. Would require dismembering a standard ecu for it's plug to join to the standard harness...

haha silly me... don't know how I came to that conclusion...

Yeah well I'm all for soldering them as I mentioned...

You cutting the Ford pin right off?

If not I'd bare a section with a razor blade... Then wrap the new bit around it so the runs up the footwell... This way you can pop the pin out of the 60pin ford connector... Slide some heat-shrink up it and seal your join... Number the wire and seal the pin with heat shrink too if your not hooking it back to the computer... Heat-shrink can easily be removed (unless you use the glue stuff which you wont need)... And then pop the wire back into the Ford connector based on the number you right on it... Should you ever need to revert it...

Cheers,
Tim

Nicco, how many wires are you connecting? Tim's idea would be handy if you have the socket attached permanently to the loom. Then if you remove the EMS, just unplug it.

Any wiring I do now I always solder and heat shrink.

I usually clean the wires with bakers soldering fluid first, then use resin core solder

Over the years I've tried crimp terminals and scotch locks. Eventually you will have trouble with them.
As your wiring in an ECU you don't want a connection to fail and leave you stranded somewhere.



I'm not sure why they would tell you this. I've never had any wiring I've soldered fail. Maybe if it was very light gauge stuff the heat might weaken the wiring

Just to add to the discussion.. If a crimp is done right it forms a gas-tight connection, which is the ideal connection for two metallic conductors. I sometimes overkill. Crimp, then flow solder, then seal in heatshrink.

All higher voltage (bigger) stuff I have seen (which isn't much) including the sub stations and power plants and high voltage transmission lines use crimp on terminals. When done right they dont fail period.



At least in my car, Ford actually crimped the wire splices in the factory loom and wrapped in electrical tape. It may be different in newer cars due to cost. For a car, if it's not in a spot that gets hot or vibrates violently or the user didn't do a bad joint that becomes dry then it doesn't matter as much. So it's up to you how far you want to go. I'd be concentrating more on your grounds and potential ground loops; wiring it up in general.

I agree... All our substation sub is Uranus Aluminium conductor... Thought I don't think you can actually solder aluminium can you? If you wanted to do that you'd be tig welding all your connectors to your conductors...

All the larger stuff as I said is crimp... At work we crimp everything except for copper earthing strap (because you can't)... Everything else is lugged with crimp terminals and anything from hand crimpers (big ones) to 50 tonne hydraulic crimp heads...

I agree... With aluminium conductors and a hydraulic crimper with the CORRECT dies fitted the joint is better than soldering... As everyone knows aluminium oxidises when it is in contact with oxygen... So the join has a paste in it and then crimped and it seals forever and never poses a problem... The aluminium never oxidises again...

The issue is with crimping is when people go all Hercules on the terminal and over crimp them... This is as bad as under crimping them as you damage the conductor... There is a fine margin for crimping just right... So hence the correct dies in a hydraulic version crimp to the right spot and deliver anywhere from 5 tonne to 50 tonne (crimper dependant) and that is it... It cannot be over crimped... The good ratcheting crimpers are the same... Do a perfect crimp... The cheap ones everybody has in the boot do a crappy job and have no limit (other than how strong the person is)... When all is right... the right crimper, the exact right sized lug (not trying to crimp a 1.5mm lug on .5mm wire) and the right technique I have no dramas with crimp lugs...

No worse than someone soldering who simply can't solder I guess... Need the technique...

I too crimp and then solder... Esp for something I really don't want coming undone (Ie earth's) and when it is smaller and seemed too small for the lug and that the crimp may not have worked properly...

And I normally use the glued heatshrink to maintain that no moisture can access the joint... Extra reassurance again...

Cheers,
Tim

Hey guys,

Thanks heaps for all that discussion. Very helpful.

From reading what you guys have said I will be:
Soldering fluid to clean
Soldering using resin core solder
Heat shrink

I have found a cheap EF ECU as well that I am going to get sent up to me. I will try and remove the female plug off it and connect my EMS loom to this. Doing it that way should let me easily be able to swap backwards and forwards between the EMS and a stock ECU, and more importantly, be easier to work with as I can solder it up on the table inside the house.


Thanks for all the help.


Cheers,
Nic