Feeler for Wiring Harnesses

[Blaine.D]

I don't what the best section to put this in so if I put it in the wrong place feel free to move it. A little bit ago, I started to experiment with creating wiring harnesses that I need for my truck by using some spare pigtails I had gotten from a Cherokee I was parting out and junkyard trips.  First I made one that plug and plays to adapt the oem harness for a ba10/5 to fit an Ax15 backup switch. Second is a plug and play harness to convert the vacuum switch that turns on the light in the dash to the later style electric switch on the transfer case. Photos below show my prototypes.Photo on the right is the oem ba10/5 backup lights connector. I got another idea that I want to do but I waiting on parts to come in to be able to do it  A plug and play harness that will allow the fan to be manually turn on with the option if desired for a time delay so the fan will stay on for a few minutes after shutting off the engine, then stops to help heat soak. Possibility another idea is a trailer plug and play harness that is the 7 blade design with trailer brakes. In addition, I can make pigtail connectors to splice in to replace some of the factory connectors if desired. I want to see if anybody was interested in any of these ideas because I would love to provide new products to the community. My plan is to use only brand name connectors such as delphi etc, plastic wire loom to protect the wiring,  and heat shrink tubing, electrical tape etc to protect solder connections if depends on if harness has it. Transfer case and Ax15 harness have not solder connections.  The more people interested the more I can cut overall costs down by buying materials in bulk.  Please give me your thoughts everyone because I want to see if this is a worth while idea for the community. Also I can look into other connectors or do custom wiring harnesses so please feel free to give me ideas. 

Edited June 9, 2020 by Blaine.D
Better Photos

[ghetdjc320]

I know there is decent interest in a stand-alone 4.0 harness. I made one myself but it’s been brought up many times before on other forums

[Minuit]

Here are a collection of thoughts about wire harness building from someone who has done it a time or two. This isn't aimed at you in particular, but at anyone who is interested in the subject. Some qualifications to what I'm about to say: I have high standards for wiring, probably higher than most, I'm a bit of a stickler for detail, and I get a little bit annoyed at some of the common things you hear repeated about wiring. If I were you and were interested in doing this either for money or just to fill a gap in the market (hopefully both), here's some of the things I'd keep in mind:

 

- The big one: splices. Splices of any type should be avoided whenever possible. That means solder splices, crimp splices, whatever. When possible, connections should be point to point with no interruptions. There are a lot of situations where splices are unavoidable. Make splices where they won't move, and make sure they are completely sealed from the elements.

 

- When building a harness, think a few steps ahead. If this thing needs to be taken apart for service, how hard will that be? Are there any connections that can be accidentally plugged together in an incorrect way? A proper harness should ONLY be able to be plugged in correctly. If you need three different four-pin connectors in the same spot, use three different styles. Expect to be selling to people with absolutely no electrical knowledge whatsoever. If you get the sense that something needs an instruction manual, provide one. This is why I don't use bullet connectors or quick-connects in any harness I build. Even if it's for personal use. I can't even rely on myself to not be an idiot 100% of the time, and I share a brain with him. You don't want a customer ruining an expensive part because they plugged the connectors in wrong. As a side note, you can buy real connector housings that fit those quick-connect spade terminals. Great thing to have a few of in the toolbox, but very bulky for what they are.

 

- Related, but make sure you keep documentation on how you build your harnesses. You want two examples of the same harness to be the same within a tolerance. Real measurements are never perfect, and there's an acceptable tolerance for everything. You've gotta be careful about this with multi-pin connectors.

 

- Don't buy pigtails and splice them together. Get some spools of quality colored wire of the appropriate gauge and the bare connector housings, contacts, and seals. That normally means GXL and TXL wire for an automotive application. I don't mind plugging one of my suppliers here: https://4rcustomswire.com/

 

- Get good at identifying connector series and manufacturers. AMC used a lot of Delphi (now called Aptiv) connectors. That's good. Unfortunately, they also used a lot of nameless $#!& that isn't in production anymore and has no information available. If you start making big complicated harnesses that have to interact with factory wiring, be aware of this and have a plan in mind to get around it.

 

- If you're going to do this for money, get the proper tooling. In my mind, anything done with a non-ratcheting hand crimper is not suitable for sale. You have absolutely no consistency with those.

 

- It's critical to establish a good reputation for yourself. I wouldn't buy a full engine harness from some guy who just started making harnesses. Start small and expand your horizons with quality, well thought out products. Offering a warranty goes a long way to ease customers' minds, but you have to take warranty obligations seriously if things do go wrong. Nothing is worse for publicity than stiffing someone on a warranty claim.

 

- Consider the possible demand for your products and the value those customers would place on your products. Know exactly how much one harness worth of supplies costs you, and know how much time it takes for you to put them together, and how much time and energy it took for you to develop that product. Price accordingly.

 

- Crimping vs. soldering: it really annoys me when people speak in a black and white manner about this. "always crimp electrical connections" "no, always solder electrical connections. No exceptions" - there are reasons that you find very few soldered connections in production wire harnesses, but there are times and places for both crimp joints and solder joints. Understand and know the limitations of both methods. Soldering creates a strain concentration right behind and in front of the solder joint. If that portion of the wiring is allowed to move with any regularity, it WILL break right where the solder joint ends. To mitigate this, provide the solder joint some form of strain relief to keep the areas immediately in front of and behind the joint from bending, or make sure that the wire flexes somewhere else. Solder is less tolerant of age and heat than proper crimp connections made with high quality components and tooling. Many types of crimp connectors are much bulkier than a proper solder joint.

 

In the real world, soldering isn't quite as easy as people like to think it is. Soldering iron tips don't last forever and must be kept properly tinned. Some soldering irons just aren't powerful enough to get large wires hot enough. Use extra flux, but CLEAN IT AFTER YOU'RE DONE. When adding solder, don't apply it straight to the tip - make it flow through the wires. Get good at doing a Lineman splice. The result should be stronger than the wire itself before you solder it.

 

- Most types of connectors have a time and a place where it is acceptable for them to be used. The two exceptions I can think of are both things you're likely to find at an auto parts store - vampire taps, and those hard plastic non-heatshrink insulated crimp connectors. Both are open invitations for moisture to ruin the connection, and vampire taps make a highly questionable connection that permanently ruins the wires it's connected to. Most of the crimp connectors you can buy at a parts store will make a garbage crimp even with a really nice tool. My advice: avoid buying anything wiring related at an auto parts store. Almost all of it is bottom-barrel garbage. You can find much better quality for cheaper from actual electronics suppliers such as Digikey, Waytek, and Mouser.

 

- Protection: For interior harnesses, I love that fabric Tesa harness tape. Quality split loom makes for a professional looking product and will help the harness survive, but the cheap stuff does not last. Use good heat-shrink tube. 3M Super 33 is my go-to tape for exterior applications. Use a multi-layered approach for protecting your harnesses.

 

If you're serious about this, feel free to shoot me some questions. The Jeep world needs a wiring harness vendor.

[Blaine.D]

@Minuit Thanks for the tips. As well for the wire supplier suggestion, really appreciate it because I was trying to find quality wiring at a decent price and only found a couple handful of suppliers. I'm serious about doing it but my only hold up is I want to make sure there's a demand or interest before I invest a lot of money into it. That's kinda the reason why I posted this feeler thread because I would totally love to do this for the community.  Currently at the moment my game plan is ordering stuff to make test runs of some of my ideas. I completely agree with starting with smaller stuff that's all my ideas at the moment is basic stuff. If anyone has more ideas for small wiring needs let me know.  

I only got one question for you Minuit at the moment. What would you recommend for a ratcheting weatherpack crimper on a budget? Currently all of the ones I seen are $100+ 

Again appreciate the tips. 

[Minuit]

18 minutes ago, Blaine.D said:

@Minuit Thanks for the tips. As well for the wire supplier suggestion, really appreciate it because I was trying to find quality wiring at a decent price and only found a couple handful of suppliers. I'm serious about doing it but my only hold up is I want to make sure there's a demand or interest before I invest a lot of money into it. That's kinda the reason why I posted this feeler thread because I would totally love to do this for the community.  Currently at the moment my game plan is ordering stuff to make test runs of some of my ideas. I completely agree with starting with smaller stuff that's all my ideas at the moment is basic stuff. If anyone has more ideas for small wiring needs let me know.  

I only got one question for you Minuit at the moment. What would you recommend for a ratcheting weatherpack crimper on a budget? Currently all of the ones I seen are $100+ 

Again appreciate the tips. 

My honest suggestion for a Weatherpack crimper is to buy once, cry once and buy the Delphi ratcheting one. It'll give you the best quality crimps and the best repeatability. $100 for a manufacturer approved crimper is pretty much as cheap as it gets. Will help your credibility too that you're using the official manufacturer tooling. If I'm not mistaken the Weather-Pack one also works on Metri-Pack 280 series, which is another very common connector line.

[Pete M]

there's always the holy grail you can shoot for, a complete new engine harness  

[Blaine.D]

24 minutes ago, Minuit said:

My honest suggestion for a Weatherpack crimper is to buy once, cry once and buy the Delphi ratcheting one. It'll give you the best quality crimps and the best repeatability. $100 for a manufacturer approved crimper is pretty much as cheap as it gets. Will help your credibility too that you're using the official manufacturer tooling. If I'm not mistaken the Weather-Pack one also works on Metri-Pack 280 series, which is another very common connector line.

Noted I'll do more researching into getting one. Appreciate the suggestions. 

2 minutes ago, Pete M said:

there's always the holy grail you can shoot for, a complete new engine harness  

I'll try and see if that can be done. The only problems I see is the hunting down the ecm connectors, tcm connectors, and other specialty connectors on the engine wiring harness. Good news is a majority of the connectors can be source new so it's possibility when I get more experience with making these wiring harnesses. 

[Pete M]

you'd probably need to either reuse them (i.e. build one at a time as old ones come in) or maybe even make a partial harness, where you run/bundle all the wires and let the end user reuse their connectors. 

[Minuit]

All I've got to say is good freakin' luck finding those stupid proprietary connectors that these harnesses are full of. That is almost certainly a big part of why there isn't already someone making new engine bay harnesses. If you can find out something that we can't (and believe me, myself and a few others who are into this kind of thing have spent a LOT of time pouring over catalogs, manufacturers, and other back channels to find a source of these connectors in their bare form with no luck)

[Blaine.D]

1 hour ago, Pete M said:

you'd probably need to either reuse them (i.e. build one at a time as old ones come in) or maybe even make a partial harness, where you run/bundle all the wires and let the end user reuse their connectors. 

 

7 minutes ago, Minuit said:

All I've got to say is good freakin' luck finding those stupid proprietary connectors that these harnesses are full of. That is almost certainly a big part of why there isn't already someone making new engine bay harnesses. If you can find out something that we can't (and believe me, myself and a few others who are into this kind of thing have spent a LOT of time pouring over catalogs, manufacturers, and other back channels to find a source of these connectors in their bare form with no luck)

I will try and see what I can find, anything is possible with the internet. Realistically unless magically a supplier pops up with these connectors probably I will figure out some type of core basic system in order to get the rare connectors while the rest is brand new components.  On the top of my head that would work roughly out to be 80% new and 20% reused components. Currently going to just stick with simple stuff to get the ball rolling.