Wiring connector advice please

[RoadRacer]

I have a few boxes of various spade connectors from over the years, and my son while wiring an amp into his Hyundai had helped himself.. with poor results. I have a good quality crimper (one of those ratcheting levered ones) but still these cheapo spades seem fairly easy to pull off - and on the really small wires it's hard to find the right size heat shrink to grip the wire. On his wiring I ended up tightly electrical taping everything individually, then as a group.

It made me wonder, what to use on a stiffly sprung, hot and exposed-to-the-elements '33, which will inevitably be a much harsher environment than a comfy compact hatchback ;)

I once used military-spec connectors for the bulkhead connectors, but that was years ago and a military friend had specialty tools.

Are bullet connectors better than spade?
Are there better quality versions somewhere?
Am I right in thinking soldering would always be better than crimping?
heat shrink vs electrical tape?
I have rolls of that split wiring loom wrap that worked well on previous projects - good enough?

I want to do the wiring properly, neatly and reliably - it seems every car I've ever bought has a rats-nest of wiring, and problems usually are in the middle of it.

[Svtfreak]

There is pluses and minuses to all.

Frankly, you don't need the ratchet crimpers. If using connectors with the heat shrink on them, get the old U style that mashes the crimp. If using non shrink ones (most common) get a set of Klein with the black and red handles. They have a tip that stakes them on. And always test pull. You shouldn't be able to pull them out. Many people believe in solder only, and that's fine. But solder can lead to corrosion (the flux) especially when exposed to elements and even worse when near the ocean. Solder would yield the best connection but must be shrink wrapped well to seal out the atmosphere. The proper heat gun (not a a torch or lighter) aids in this.

The most foolproof way to ensure good integrity is to minimize your connections. Don't splice in extensions, don't splice in T's in weird places to save wire, etc. The fewer the connections, the better your integrity.

My rule of thumb, I solder mid wire connections and shrink wrap well, and then use stake ons at wire ends where connects to equipment. On high current stuff like headlamps, I solder and shrink wrap, except at the ground connection I use stake on. On lower current stuff that isn't so safety critical, I may throw a butt splice but otherwise I try to avoid those.

I have never had a malfunction due to a bad electrical connection *knock on wood!* except one bad ground once and one defective fuse block that's 3 cars built and countless stereo and amplifier installs. It works for me.

[edwardb]

Soldering vs. crimping is debated a lot. DD's typically have all the pin connectors crimped and no solder. But to be fair those are done in controlled factory environments with specialty equipment and careful checking. Pull tests, etc. I know. Used to work around that stuff. For home use, it's possible to produce high quality crimps with the right tools and close monitoring. IMO very careful (and minimal) soldering can add a level of reliability and I do my share. But done poorly and especially allowing the solder to wick up the connecting wires can lead to premature failures. Unless you have the right soldering equipment and some experience, I'd probably recommend against it for small gauge wires. Focus on getting good crimps. I always have extra pins and wire and practice and test a few times to make sure all is good.

I completely agree with Svtfreak's recommendations. Work to minimize connections. I don't do splices unless absolutely necessary. I also avoid butt connectors. I have a couple in my latest build, but only use the heat shrink variety and only if there isn't another option.

I highly recommend shrink sleeving over electrical tape. Frankly, I wouldn't use electrical tape for anything except maybe for over-wrapping harnesses. Even then there are other and maybe better choices. Never as a substitute for shrink sleeving. I get my shrink sleeving from DelCity.net. They have many different varieties, and a few 4-foot sticks in several sizes will last the entire build. I strongly prefer the dual wall variety, which has an adhesive lining and makes a really solid and weatherproof connection. https://www.delcity.net/store/Dual-Wall-Tubing/p_327.h_77061. The only similar sleeving I've found in retail is at West Marine. They have a good selection but it's in short pieces and many times more expensive.

[RoadRacer]

If using connectors with the heat shrink on them, get the old U style that mashes the crimp. If using non shrink ones (most common) get a set of Klein with the black and red handles. They have a tip that stakes them on.

Hmm, ok, I'll take some apart and see what you mean by "stake on". That doesn't seem like what I have lying around.

Here's my crimper, stripper and selection of (what seem like) cheapy connectors.

68086


Frankly, I wouldn't use electrical tape for anything except maybe for over-wrapping harnesses.

Good to know, thanks.


I get my shrink sleeving from DelCity.net. They have many different varieties, and a few 4-foot sticks in several sizes will last the entire build. I strongly prefer the dual wall variety, which has an adhesive lining and makes a really solid and weatherproof connection. https://www.delcity.net/store/Dual-Wall-Tubing/p_327.h_77061.

Yes, this looks exactly like I remember from old builds. I'll get some more from there, thanks (and a new heat gun, seem to have lost mine)

[RickP]

I really like the heat shrink/crimp type connectors that Del City sells. Browse any connector and filter heat shrink/crimp. https://www.delcity.net/store/Terminals/

They are far and above any type connector you can obtain at your neighborhood parts store. Proper terminal for AWG size, heat gun, decent crimper and your good to go!

[boBQuincy]

It would probably be best to look to the construction equipment industry, where vibration, heat, and exposed-to-the-elements is the typical environment. Deutsch DT (or DTM for smaller wires), AmpSeal, or equivalent work well in this environment.

The DT and AmpSeal machined pins can be crimped successfully in the field, most stamped & formed terminals are difficult to crimp properly at home.

For unsealed terminals soldering can prevent moisture from wicking up the wire, heat shrink tubing with sealant helps too and provides some strain relief.

Cross-linked polyethylene wire (GXL, SXL, or TXL) is better for most applications than PVC insulation.

[mikeinatlanta]

My advice would be to not use any connector available at an automotive supply and stick with aviation quality or equivalent. Although they look the same, aviation connectors have two crimps, one on the conductor and another on the insulation. The second crimp acts as a strain relief preventing the most common problems.

This is a common aviation style connector.
68101

Here another style without insulation but with strain relief to show what I am talking about.

68100

EDIT: This is all of course for situations requiring this style connector such as connecting to a relay, circuit breaker, or terminal block. Wire to wire connections should always use a quality plug style connector with strain relief such as Deutsch DT or Weatherpack.

[mikeinatlanta]

Regarding waterproofing. IMO, the only way to waterproof automotive connectors is to put them in a dry location and take measures to keep them out of spray. While heat shrink may look like waterproofing, on a normal connector water will still wick up the end of the wire at the exposed tip of the copper strands. If you need waterproof, buy actual waterproof connectors. If not an option on a splice, super high quality sealer lined heat shrink or dip the assembled splice in plasti-dip.

[erlihemi]

Lots of great input here! I'll echo Mike on the dual crimp connectors as that provides physical strength separate from the electrical connection. Small gage wires especially like this style. I prefer the non insulated so I can see the quality of the crimp. Most shrink sleeves that can go over the spade won't shrink enough to seal the splice correctly. There is stuff like plastidip just for the application. If its under the car I like to put the liquid sealer on and then slide the shrink tube over it. The shrink tube with the sealer already in it is too pricey and hard to find when I am ready to use it... I also like the split Velcro heat shield material with the loom cover added to the outside for the engine harness when possible. If it says 3M on it its probably good.

[Svtfreak]

These are the crimpers I am referring to. They are great for making crimps that will not pull off. However, as I mentioned, they cannot be used on crimps with the heat shrink made on it. They can puncture the shrink which then tears from that point when heated. Yours would work for heat shrink type but I might would invest in a better brand.

https://www.amazon.com/Klein-Tools-Insulated-Non-Insulated-Terminals/dp/B0006M6Y5M