Differences between amateur and professional wiring? Options

[Tdskip]

OK guys - we have some very talented people here and I'm hoping to bring my wiring skills up a level.

What separates amateur wiring from a pro level? One item that comes to mind - no use of Harbor Freight connectors (which I am guilt of).

What else comes to mind?

[76-914]

Solder your crimp fittings to take it to the next level. All solder joints should be shiny when completed. Connectors should be marine grade heat shrink style that require a heat gun to complete. Wiring should be bundled neatly and routed in a manner that does not cause stress on any of the wires. Wires should be of the required size, color coded or labeled in a manner that makes identification easy. That should get your started. The real pros will chime in shortly. (IMG:style_emoticons/default/beerchug.gif)
EDIT: buy a good set of crimpers. They'll be north of $70

[914forme]

Wire should be SAE Type GPT wire at minimum. Use proper crimp connectors, not the cheap crap you find at Autozone or Walmart.

Proper Crimpers and tools go a long way. Heat shrink, strain relief, and proper wire looming

But it is very hard to say what Pro wiring surely is. As various levels are used across multiple industries.

Soldering should not be used in an automotive strand wire application.

I would use heat shrink with adhesive.

Then if your stepping up to the top level your going to go with wiring that has been twisted, and loomed together, and using high end connectors. Weather-pack are like the low end connectors, and it just climbs in cost and complexity from there.

Wiring goes up, if you see anything that says MIL on it, run, it will cost you $$$$.

Label everything, and then clear heat shrink the label. They actually make printers that print onto heat shrink, I still add clear over it to keep it protected.

After that I can say I build all my wiring on paper first, then in string, then on a board or bench, then in wire.

Not a pro anymore, I used to wire up one-off prototype stuff, it was all MIL spec, and all in white, with numbers at each end. And a spreadsheet was used to keep it all straight. You can get the MIL spec wire in colors other than white, it was just easier in our application to stock white and use it for everything.

[bandjoey]

http://www.visioneng.com/wp-content/upload...rol.15SEP16.pdf

I learned a lot from this site. I'm kinda an advanced amateur.


....Soldering should not be used in an automotive strand wire application.
Why Not?

[Superhawk996]

Solder your crimp fittings to take it to the next level.

EDIT: buy a good set of crimpers. They'll be north of $70

Agree completely that you need a good set of crimpers. Note that crimpers are specific to the type of termination you are using (Spade, Molex, Weatherpack, Deutsch, Amphenol, etc.). 914's use really low end spade connectors which are really low tech but cheap and easy to fix which has it merits. Mac Tools and Snap-on both have some nice crimers that basically roll the crimp inward rather than simply crushing it from both sides like cheap crimping pliers.

....Soldering should not be used in an automotive strand wire application.
Why Not?

Beware of soldering vehicle wiring. The solder wicks up into the wire and creates a non flexible termination. If the soldered termination is subject to vibration (and it will be in a car) it will fatigue and crack over time. I know there are DoD military vehicles with soldered connections and I can tell you horror stories about that wiring and associated military style Amphenol connectors. Likewise I've seen plenty of race cars with soldered connections. Some good, some terrible. Race cars are not typically subjected to decades of use. Not saying don't ever solder but minimize it and for sure don't over do the solder and have it wicking up into the wire beyond where the crimp ends. Personally no solder for me.

Trying to create a shrink wrap strain relief often creates more havoc that what it was intended to prevent. Automotive wiring needs flexibilty at its termination to survive. Nothing wrong with a little bit of strain relief where harness split's into Y formations though. Again, don't over do it. Flexibility is critical to survival.

You will not find soldered connectors (other than on a mid harness splice) on modern vehicles. Not for cost but rather that you want the flexibility of a crip termination and the lack of vibration fatigue problems.

As previously referenced what sets the men from the boys:

1) Neatness. Braided sheath, convolute, or simple wiring tape really makes it tidy.

2) Leaving enough service length so the connector isn't severely flex'd and so it can be removed later without stressing the wire.

3) Properly crimped connections. Crimp them, then pull on them - hard, they should not slip or give. A properly crimed connector will not let lose before the wire itself breaks.

4) Color coding and consistency. Don't be cheap. Buy quality wires with unique tracer markings. Plenty of sources for vintange and German wiring colors.

https://www.riwire.com/

Look at Jeff Bowlsby's wiring harness designs. Very nice and a good benchmark to shoot for.

[bbrock]

I'll just add a little to the already excellent advice given. You can buy OEM (AMP) connectors at digikey. They are high quality and an exact match of what came originally in these cars. Here is a list of some of the part numbers I used rebuilding my harness:



You can use generic grommets but OEM are still available but a bit of a PITA to source. Most of the grommets are blanked sealing grommets so IMO, using open style grommets is not at a professional level as they won't seal out water or air like the originals. Here is a list of part numbers for most of the grommets. If you want the spreadsheet that includes source links, PM your email address.



As for soldering, follow the earlier advice and do not solder terminal connectors for the reasons @Superhawk996 described. From what I have read, soldered terminal connections are not allowed in aviation applications. That says something. However, DO solder wire splices if you have to make them. Use a lineman's splice , solder it, and protect it with heat sink. I match the heat sink color to the wire and add match tracers with colored sharpies just for that extra touch.

914Rubber sells OEM harness tape if you want to match the original. You can also get it on ebay. I think the brand is Telsa but can't remember for sure.

Hope this helps.

[Superhawk996]

Here is a list of some of the part numbers I used rebuilding my harness:

(IMG:style_emoticons/default/smilie_pokal.gif)

That is an incredibly useful list of small parts. Thank you for sharing. It must have taken a ton of time to research all those part numbers.

@SirAndy

That list should get moved somewhere for ease of acess long after this thread disappears off the front page.

[Costa05]

If you are a bit detail obsessed like me, I found that brake cleaner, hard nylon brush, then a soapy water can clean up a tired existing harness pretty well. Rewrap it with new cloth tape from HD.

Also I would add new fuse terminal block to the four main high amp feed wires (10 ga. red) coming off your battery terminal block. I think the stock setup is a bit under designed in my opinion (mine was) Cheap easy insurance.

[AZBanks]

Great wiring write-up.

https://www.rbracing-rsr.com/wiring_ecu.html

[gereed75]

That is a really good guide!

The Home built aircraft “industry” is a good place to find high quality advice, tools and supplies. One of the go to sources is https://www.steinair.com/. They can supply a wide variety of wiring supplies of good quality in the type of quanties appropriate to our kind of use. Maybe of most value is that they have sorted through the quality maze and provide great quality vs. value for the hobbiest/near professional

In addition, this ste http://www.aeroelectric.com/articles.html#...20and%20Splices Is a wealth of knowledge on all things electrical in layman’s terms. It is focused on aviation but there is a lot of elementary how to stuff there about correct solder joints, crimping, termination etc. written by a guy known as Electric Bob in the home builders world. Entertaining writer and also a very KISS engineer.

Not affiliated to either

[Superhawk996]

Great wiring write-up.

https://www.rbracing-rsr.com/wiring_ecu.html

Awesome link to behind the scences of high end Motorsport wiring.


Two great quotes that reflect the unfortunate ugly side of motorsports

"A person we know used to wire high end off the road racing vehicles where the total wiring bill was often North of $25,000.00 for parts and labor and he did not want to do it anymore as it was tough getting paid for the work, not to mention all the travel and fighting clients. "

"We once built a new harness for a long term racing project, ready for installation. Due to unrealistic attitudes and unappreciative recipients we simply cut up the harness and saved the connectors. Expensive lesson."

[barefoot]

If you are a bit detail obsessed like me, I found that brake cleaner, hard nylon brush, then a soapy water can clean up a tired existing harness pretty well. Rewrap it with new cloth tape from HD.

Also I would add new fuse terminal block to the four main high amp feed wires (10 ga. red) coming off your battery terminal block. I think the stock setup is a bit under designed in my opinion (mine was) Cheap easy insurance.

Agree here, I had to install a new to me main harness & was afraid of a short somewhere.
here's my new fuze box.

[falcor75]

Dont use any kind of tape to wrap your harness with (yes it may be original but there are better options available) I used the braided nylon sleeving often found in industrial robots etc when I did my aftermarket ECU install. Just terminate the ends with heatshrink with glue and it looks great.

+1 on the correct crimping tools and also get a proper set of pliers for removing the insulation on the cables. Its worth the $20 instead of using the old worn sidecutter !

[Tdskip]

I thought this would be a useful topic, thanks for all of the great discussion and information.

Are there any specific crumpets recommendated?

[gereed75]

My recommendations from https://www.steinair.com/product-category/tools/page/2/

SKU: SAT-001 crimpers

SKU: SAT-030 crimper dies

SKU: SAT-018 pin crimper

SKU: SAT-005 wire strippers

The crimper and dies for crimping insulated terminals, the pin crimper for connector pins and un-insulated terminals, and the wire strippers for general use.

Have fun

[bbrock]

I've been really happy with this budget crimping set for occasional DIY use.

https://www.amazon.com/gp/product/B00Y7M7SG...=UTF8&psc=1

[ClayPerrine]

http://www.visioneng.com/wp-content/upload...rol.15SEP16.pdf

I learned a lot from this site. I'm kinda an advanced amateur.


....Soldering should not be used in an automotive strand wire application.
Why Not?

I completely disagree with the comment about not soldering the wires. That is an old wives tale. If you take a close look at a factory 914 harness, you will find that every connection on it is soldered. When I rebuilt the DME harness for the 4.0L motor, every connection on it was soldered when I disassembled it. If you do it right, soldering the connections is a very good, reliable connection.

[porschetub]

http://www.visioneng.com/wp-content/upload...rol.15SEP16.pdf

I learned a lot from this site. I'm kinda an advanced amateur.


....Soldering should not be used in an automotive strand wire application.
Why Not?

I completely disagree with the comment about not soldering the wires. That is an old wives tale. If you take a close look at a factory 914 harness, you will find that every connection on it is soldered. When I rebuilt the DME harness for the 4.0L motor, every connection on it was soldered when I disassembled it. If you do it right, soldering the connections is a very good, reliable connection.

(IMG:style_emoticons/default/agree.gif) never had an issue with soldering once I got good @ it (IMG:style_emoticons/default/biggrin.gif).

[Costa05]

If you are a bit detail obsessed like me, I found that brake cleaner, hard nylon brush, then a soapy water can clean up a tired existing harness pretty well. Rewrap it with new cloth tape from HD.

Also I would add new fuse terminal block to the four main high amp feed wires (10 ga. red) coming off your battery terminal block. I think the stock setup is a bit under designed in my opinion (mine was) Cheap easy insurance.

Agree here, I had to install a new to me main harness & was afraid of a short somewhere.
here's my new fuze box.

Exactly. That is a clean install.

[Superhawk996]

I completely disagree with the comment about not soldering the wires. That is an old wives tale. If you take a close look at a factory 914 harness, you will find that every connection on it is soldered. When I rebuilt the DME harness for the 4.0L motor, every connection on it was soldered when I disassembled it. If you do it right, soldering the connections is a very good, reliable connection.

There is material science behind the recommendation. It is not an old wives tale.

A stranded wire that is soldered esentially becomes a larger gauge solid wire. That singular wire then work hardens due to vibration. With enough time and vibration it will break.

The analogy is to take a coat hanger (single strand wire). Now begin bending it back and forth (i.e. low frequency vibration). Eventually it work hardens and breaks. if you speed up the the bending (vibration frequency) or the amount you bend the wire (the vibration amplitude) the faster it breaks.

Copper work hardens in the same way that steel does though it takes longer.

This is the reason automotive uses stranded wire. Multiple smaller gauge wires are more flexible than a singe larger strand and work harden over a much longer period of time.

I'm not sure what harness you're looking that is soldered. There are many crimped spade connectors that have a bit of insulation over the spade to prevent shorts but the connections underneath are crimped not soldered.

The sole exception that I'm aware of is I think the 14 way engine harness "bullets" are soldered at the very end. They are then inserted into the 14 way plastic connector and capped / clamped in position such that those little bullets are not exposed to vibration the way the rest of the spade connectors in the engine compartment are. The wires coming out of that 14 way harness are able to flex freely. I would go look to be sure but my engine harness is currently in storage. Going from memory the only other connector that uses those soldered bullets is the trans reverse switch which is notorious for breakage.