Tell me your top wiring tips (my harness is in the mail)

[Rusty76]

This monday my BJ offroad wiring harness is due to arrive. I have zero know how on wiring. I know I will figure it out but getting some tips from you pros is always helpful. This is for a 76 Wagoneer. Rebuilt everything is in but I have not started it up yet. Decided I better replace the old patched electrical. I'm super excited to learn and work on this aspect of the build.

Thanks everybody

[Shep 762]

If it takes too much force you're doing it wrong. No need to horsef**k a connector, look for locking tabs, push instead of pull etc.

[FSJunkie]

No electrical tape. No adhesive tape in general. It turns gooey, makes a mess, and unravels with time. Use heat shrink or dry vinyl wrapping tape tied off at the ends.

No plastic sleeve connectors crimped in place. Use bare metal connectors. Crimp them to the wire, solder them to the wire, then heat shrink over. I really like the adhesive-lined heat shrink because it forms an airtight seal so no corrosion can form inside the wire and connector.

No splice locks. Hell no. Those are the worst things ever invented.

Tooth lock washers on grounding terminals. They cut through paint and corrosion to make good contact.

Proper bundling and wrapping to keep wire runs neat and organized is your friend.

[Full Size Jeeper]

Take a lot of pictures of the layout of the old harness. Also draw out on paper the layout of the wires and any plastic hold downs or brackets that you take off.
Mark with tape the new and old connectors at the same time. You will think you can just remember where it all goes, but might forget something.
(example)
alt. plug A
alt. plug A
a/c plug B
a/c plug B

Once you get the old one out, lay one on top of the other and check length. Easier to mod the new harness on the bench if needed. Lots of up front work, but will make the install go smoother.

[Kaiserjeeps]

Get the harness in and make sure you have a permanent destination for each wire before you cut. Cut long, fit it, then cut one more time for a perfect fit. Doing it twice is way easier than trying to make a wire longer.

Epoxy heat shrink is the only way to go. You will need a heat gun. Don't bother with regular heat shrink. It does not seal moisture out.
Soldering each connector as previously mentioned will make a connection that will last a lifetime. Cover it with good heat shrink.

Document each wire color and where it goes. Start to finish. You will be glad to have that later if something starts acting up.

Invest in quality crimpers. REAL crimpers. Then crimp and solder and heat shrink away.

If you must use crimp connectors with no solder, only use epoxy filled heat shrink connectors. That at least seals the connection.

Do not use acid core solder flux. Thats for radiators and metal. Use rosin core flux only. Acid based flux causes corrosion on your solder work.

Cover wire runs with wire loom. The standard thing is ribbed plastic. For restoration uses, asphalt covered loom is available. For super heavy duty abrasion resistant covering, woven poly is out there for stuff like tractors.

For under body weather proof connectors, weatherpak can't be beat. That involves the special terminals, seals, connector shells and very important, the right crimpers.
The packard 56 connectors found on every jeep (older) out there are open and subject to corrosion.

I just built a complete new harness for an old dozer. I soldered every joint and covered it with heat shrink. Original wire colors and everything.
I have all the faith in the world it is as good as it can be. Do the best that you are able. It will matter later.

[67GMC]

Second to soldering, I typically use the "western union wire splice" method of making joints. Then cover the joint with shrink rap. I learned this in high school electricity class.

Soldering is great if you have the wires on a bench. I've also seen a fair bit of poor soldering that causes sharp points that poke through the insulation and cause issues. Never had a western union joint come apart.

Agree that Scotch Locks (those blue plastic crimps) are products of satan and just designed to cause more problems. I had a Cherokee that the previous owner had installed a remote car starter/door unlocker. All Scotch locks everywhere. What a mess to fix in a tight spot under the dash etc.

[Rusty76]

Great! Thanks everybody. Looks like I've got lots of research to do before I start.
Hopefully install new tank today and start plugging away at the wiring.
Thanks for taking the time to help. Look forward to updating this thread with success.

[tgreese]

My approach is similar to Nigel's.

To make a solid, weatherproof splice:

Uninsulated butt connectors. (Del City, Waytek)
Good crimping pliers. (Amazon)
Automatic wire strippers (nice to have - Amazon).
Kester 60/40 or 63/37 tin-lead rosin core solder. Fairly large size, like 30 or larger. (Amazon)
Weller soldering gun. (garage sale or Craig's list, or Amazon I suppose)
Extra paste or liquid flux for old wires (Kester brand NLA, use MG - Amazon).
3M adhesive heat shrink tubing (Parts Express, Waytek, Mouser or Digikey).
Cheap heat gun (I have a nice green one from Grizzly in the garage, plus a small one on my indoors bench; Amazon, Harbor Freight, others).

No cheesy/gooey plastic electrical tape.
Practice on scrap wire.
Be sure to put the heat shrink on BEFORE you crimp the connector.
Hot iron, get in, get out. Let the work melt the solder.
Adhesive heat shrink FTW.

I like to bundle everything in split loom and secure with black tie wraps aka zip ties (Parts Express). You can buy "automotive grade" split loom which has a higher melting temperature, but I have used the cheapest split loom I can find and had no issues. You can also buy the tees for split loom that the auto manufacturers use to branch split loom, but I think that's mostly to make the installation fast on the assembly line. I just bring the wires out of the split and put a zip tie around the loom to keep the wires from unzipping down the loom, then start another piece of loom.

Use NEW shakeproof washers (aka toothed or star washers) and a dab of dielectric grease on ground connections.

Do own a multimeter? Suggest you get one and learn to use it. An exceptionally powerful and useful tool.

[levelhead]

All good advice

[Rusty76]

Wow I've been doing loads of research and I had no clue about the Solder Vs Crimp debate. Literally changes in every article.

[tgreese]

There are opposing views.

Solder makes a good joint whether you crimp well or not. The argument against is - it's more work, and the transition from solder to bare wire is a stress riser that can fatigue the wire at that point. As you know, you can break copper wire by bending it back and forth repeatedly to cause fatigue. This is why they use stranded wire in automobiles - the individual strands can bend more easily without fatiguing. Solid wire is used in buildings because it's immobile in the walls.

Suggest if you solder, put your joints where the wire is not going to move a lot, or tie the wire down, or both. The heat shrink also helps to stiffen the joint, and avoid fatiguing the wire.

A well-executed crimp is said to be as good as a joint electrically as a soldered joint, maybe better. Supposedly the extreme point pressure of a proper crimp welds the two materials together. However, specialized crimping pliers that can make these excellent joints are expensive, and only work with specific connectors.

Soldering is still used everywhere in electronics. Indeed, it seems like industry has gotten away from mechanical wiring like wire wrap (popular a couple of decades ago) and moved instead to tiny surface-mount components that are held in place by only solder.

If you really hate the idea of soldering, suggest you get the adhesive-lined plastic insulated butt connectors, and buy a ratcheting crimping tool made for those connectors.

[Rusty76]

Thanks again for the help. Ok I've pulled out the old harness and ran the new EZ wire harness to the designated spots (engine, front, back, dash, steering column).

I will admit I was pretty overwhelmed after taking the old harness out. It crossed my mind that this might be the step of this build that never allows her to move under her own power. After I sent the wires to designated spots I feel better and am up to the challenge. So the first round of questions.

1. Some of my old connections such as the Temp Sensor has the push on style.
Does a guy just use the ring connectors with heat shrink and a small nut?

2. So it looks like I snapped a bunch of pins from the ''Pin Connection" and a couple
other ones from the gauge cluster. Initially I took this as a sign that I should buy
a sweet new Dakota Digital cluster. After a quick price check I quickly decided I
should try to fix. Can I get new pins? I read a good thread about how to fix.
looks doable.


I had this whole week off to wrench and maybe finally get this thing running before the snow melts. My little ones have been sent home from school. So daddy daycare starts tomorrow. Might start with some wiring. IMG_0712 by , on Flickr
IMG_0713 by , on FlickrIMG_0714 by , on FlickrIMG_0715 by , on Flickr

[Rusty76]

One more question. I bought the larger harness for my 76 Wag. It has lots of extra wires such as power locks, windows. The instructions mentions just to cut it off as close to the fuse box as possible. Am I reading this right? Wouldn't those cut wires be hot? Maybe cause a fire? Thanks again!

Stay Healthy everybody..

[chubbinius]

You can either work on re-attaching the pins, or pick up a new circuit board here

https://stores.partsdude4x4.net/circuit-board/

They also have a replacement pigtail if you can't get the pins out here

https://stores.partsdude4x4.net/instrument-cluster-harness/

Hope that helps. On the cutting off the extra wires, I would recommend that you just wrap them and secure them rather than cut them off...that way if you want to upgrade or add a circuit later, you have the wires to do it.

[Rusty76]

Hi thanks for the tip. Called Partsdude today. They don't have the board for my 76.
Too bad that would have been perfect. I think I'm going to try and fix the pins.
Found a great thread about using super small screws to act as pins.

I started separating the front light wiring from the engine bay wires.
The organization was a big help is thinking I just might pull this off.
With lots of help from this forum. Which I'm lucky to have found.
Stay healthy everybody.