HELP! Aftermarket wiring harness

[bikersmurf]

Yes, you can re-warp with regular electrical tape, or get some braid - painless sells a kit for that too.

Rewrapped harness with non sticky black electrical harness tape. If you dont have time to do it right, when are you going to find time to do it again.

I recommend that you DO NOT USE regular electric tape. You don’t need to buy it from Painless, but use a non-sticky tape that fuses with itself. Electric tape does not hold in a warm environment over time.

In ‘96 I used ‘Magic Wrap’ from Home Depot... it’s still standing up well. I’ve also used 3M tape designed for the purpose. Electric tape will become a sticky mess in no time.

 

[SHAUNBLACKMON]

So, my thought is to buy a generic harness (or make using correct color coded wire), place it side by side to my existing one and recreate a OEM Type harness, replacing the connectors I can source and using original ones that I can't. Best of both worlds, new harness with correct colors going to the right places.

 

[emac]

I recommend that you DO NOT USE regular electric tape. You don’t need to buy it from Painless, but use a non-sticky tape that fuses with itself. Electric tape does not hold in a warm environment over time.

In ‘96 I used ‘Magic Wrap’ from Home Depot... it’s still standing up well. I’ve also used 3M tape designed for the purpose. Electric tape will become a sticky mess in no time.

Thats why I wrote" NON sticky electrical harness tape"

 

[rkymtnflyfisher]

Thats why I wrote" NON sticky electrical harness tape"

Or reverse wrap the first layer and come back over it with the sticky sides together. The tape doesn’t stick to the wire harness, it sticks to itself, and it’s easy to cut off and remove if needed. Buy good tape, like Super 33.

 

[Solace in Solitude]

Haven't been able to source the connectors and Coolerman posted that he does not have the '77 connectors to do the harness anyway. I have done several aircraft harnesses but am wondering about sourcing the wire in the different colors w/stripes as required on the wiring diagram. Brain is only working at 10% as I have the flu right now. I bought a 1,000' reel of white/black 16 ga. ground wire from Fastenal (smallest quantity I could buy) Price was about .17 cents per foot and I will be willing to sell some if it as I only wanted about 150 feet.

@Coolerman sells most oem color wires, if you want to try to match the schematic. He also sells harness wrap,

EDIT: You might try sourcing a '77 harness and salvaging the Toyota connectors from it.

 

[YoYoHo]

solder all your connections, then heat shrink.

Please don't ... solder has no place in Automotive harness applications unless you get desperate or are working on board mounted pin outs.

You can get almost every Toyota connector you want of Alibaba very cheaply or just re-pin your current cases / shells . Your biggest limitation is going to be crimp tools unless you stick with a certain style of connector such as AMP / WeatherPak / Metri-Pak etc. I have more $$$ tied up in Crimpers than a lot of people have in their trucks lol.

Just comes back to how anal you want to be but a little knowledge will save you a lot of issues.

If you decide you want to do it is RayChem instead of loom wrap I just picked up a 20ft container full of it and can help you out

I usually avoid OEM junk as I hate GXL Wire and spade connectors and stay in the Tefzel / Deutsch world. There are some good instructional courses on line for Motor Sports stuff . For example - Wiring Fundamentals, Zak is far from the top of the Harness world but he has done a great job on explaining it and making is easier for people to start out cheaper .

 

[YoYoHo]

Or reverse wrap the first layer and come back over it with the sticky sides together. The tape doesn’t stick to the wire harness, it sticks to itself, and it’s easy to cut off and remove if needed. Buy good tape, like Super 33.

The main reason you avoid glue backed tape is because when you flex the loom it will open up on one side and compress on other. If you really care you can do Concentric Twisting before you loom it. It is also worth flossing the loom if you are going that far though then you are in a different work of stress relief and service loops.

 

[middlecalf]

@YoYoHo I haven’t started into unwrapping and fixing as needed my ‘63 harness but you’re saying that when I do I’m going to find mechanical splices where splices exist under the original harness wrap and not soldered splices from the factory?

 

[SHAUNBLACKMON]

I find it hard to believe that starting over with new and doing it CORRECTLY is not better than rebuilding the existing one. Key word correctly. And if it is your forever vehicle, you did it, so you know what and how you did it which makes it easier to fix down the road. Places like Granger supply has appropriate color wires and tons of different connectors. I think connector types are the least of our worries on a rebuild,,,, if you put and change from basecoat/clearcoat, fender flares, aftermarket bumpers, lights, radio A/C, PS,,,, all these change the factory original, so why stress over wire color and connectors? This thread has made me want to do a more exhaustive, correct, wiring harness tho.

 

[John McVicker]

Trust us...adapting an aftermarket wiring set up is a major pain.

And another reason to repair your existing harness is you will alway be able to refer back to the OEM schematic for all future work.

 

[SHAUNBLACKMON]

Trust us...adapting an aftermarket wiring set up is a major pain.

And another reason to repair your existing harness is you will alway be able to refer back to the OEM schematic for all future work.

I have the schematic for 74 wiring harness, that is how I was going to build a new one. Use the old one on a plywood board as suggested and with the schematic, build a brand new one

 

[emac]

I think I recall a "mechanical splice' in a few places when I redid my harness. I had several places that needed the last couple of inches of wire replaced. I soldered and shrink wrapped the new wire into place. Sorry @YoYoHo .

As @John McVicker said, several of the factory connectors would be a real pain to splice into....like the gauge cluster. The only reason I could see using something like painless is if the build was totally custom (V8, modern gauges, etc.)

 

[John McVicker]

Right now, if my wife was in on this she would say ‘fine, do whatever you want!’.

Just kidding you tho...you can indeed adapt a new harness and make it work just fine. I just think it’s a lot more work for you that way. But it can be done.

 

[Coolerman]

I do sell MOST but not all of the non-sealed connectors and mating terminals for the FJ25/40/45 trucks up to 1978. After that Toyota started using some really weird sealed connectors that are simply not available.

I do sell ALL the wire colors and gauges for the FJ25/40/45 up to 1978. After 1978 Toyota started using a lot of smaller gauges I do not carry. The BJ series used some really large 10ga stuff that I am starting to stock. Toyota only uses 5 wires gauges up to 1978 10ga, 12ga, 14ga, 16ga, and 18ga. Most of the FJ40 wiring is 16 and 18ga.

GXL/SXL/TXL is the wire type used by Toyota and every other auto maker to this day for MOST of a vehicles wiring. It is far superior to the GPT type Toyota used in the past. (With the exception of the early FJ40 and the FJ25 which used a wire type that stays very flexible for the age it is.)

I do sell non-adhesive harness tape. PLEASE do not use electrical tape regardless of it's quality, to tape a harness. The glue will melt with under hood temps creating a sticky nightmare for you if you have to open it up later.

Some facts for you guys:

Toyota used splice crimps to make internal harness splices. These are simply brass U shaped pieces that are crimped with a non-insulation open barrel crimp tool like the Hero BL-255. I have NEVER seen one fail in a harness I have worked on. I use them when I build new harnesses.

Toyota did not solder wire to wire connections but they DID solder wire to bulb housings. However I do seal the ends of power connections like the fusible link and alternator connections to keep out moisture to slow the corrosion process. I crimp the connection first, then flow just enough solder to seal the end. I have seen MANY failures in power circuits due to corrosion at the terminal wire interface. Just ask any FJ60 owner about their fusible links...

In the FJ25 and early FJ40 Toyota DID use harness lacing to shape the harness before wrapping it. I guess string was cheaper than tape at the time?

Proper tools: Terminal Crimpers
It was mentioned that someone had more in their crimp tools than some have in their entire trucks...
I can relate! Crimping terminals to wires using the proper tools is essential to building a reliable harness.
I own at least 8 sets of crimping tools. However, you do not need to spend a fortune to work on your FJ40 wiring harness. A good $45.00 set of open barrel crimpers (That I sell) is all you need to do 95% of the terminals on the truck. This set of crimpers will also crimp closed barrel terminals (like ring terminals) with an optional die set.

Repairing you own harness:
If you want to help keep re-sale value of your truck, do NOT install an aftermarket harness! There will be no schematic for it and the next owner (unless he is an experienced auto electrical person) will have no idea how to troubleshoot it. It is ALWAYS better to repair the OEM harness.

Lay the harness out on a 4x8 sheet of plywood. Orient it so that the drivers side of the harness is on the left just like it is in the truck.
I use rolls of velcro and a staple gun to hold the harness in place. Use a razor blade or box cutter to CAREFULLY cut through the outer tape layers. Do NOT cut the binding tape!!! This is the tape at every junction that holds the harness in shape. If you cut that, your harness will be hard to get back into it's original shape. If you do cut it, use zip ties to hold the harness in shape.
Once you have the harness entirely un-taped. Start on the drivers side and inspect the harness wires for any damage, scarped off insulation, heat cracks, melted wires, missing connectors. Start making a list of all the defects. The headlight and tail light circuits are the most common circuits for melted wires.

If you find melted wires: Start tracing the melted wire back to where it either terminates in a connector or is spliced to another wire. It is best to replace the wire from one end to the other including the terminals. Overheated brass terminals have a very hard to remove oxide on them. Carefully try to separate the melted wires from each other without tearing the insulation from them. Sometimes it is simply not possible and you will have to cut sections out. Do not work on more than one section at a time! It is easy to lose track of what you have done. Check off the items from your list as you repair them.

Wires that are under the hood will suffer from heat damage or physical damage. To replace them follow the wire back to where it exits the harness then go back at least 2-3 inches inside the harness and cut it off inside the harness. Make sure your new wire matches the gauge of the wire you are replacing. Measure your new wire and then make it 2-3 inches longer than needed. You will thank me for that tip later...

Make SURE the splice will be inside the harness!!! Splices tend to be inflexible and need to be secured inside the harness. I use splice crimps to make all splices, but there is NOTHING wrong with soldering the splice. Whichever method you use, be sure to cover the splice with dual wall heat shrink tubing. (The type that melts a glue that seals the splice). Do not put the connector on the end until you have all the splices done and the harness taped enough to hold it's shape! That way you don't get a surprise when your wire is too short.

While you have the harness apart is a good time to add any wires for optional stuff... If you do add wires: DOCUMENT THEM!!! 10 years from now when your amplifier quits you will be able to pull up the documentation and see exactly where the wires go...

Tape the harness back up with non-adhesive harness tape. Contact me when you get to this point and I will reveal how I tape a harness easily.

Hope this long winded post clears up the mystery of working on your own harness....

 

[ToyotaMatt]

EZ Brand 21 Circuit MINI , is the only way i Roll..........

- Great phone TECH Sean , is a trooper

- fused box fits and bolts to the 2 factory 10mm tabs ( HUGE point in my book )

- IMO better engineering and parts overall quality then painless

just my :

 

[Coolerman]

You can get almost every Toyota connector you want off Alibaba very cheaply...

Your Google skills are far superior to mine if you can locate vintage Toyota connectors like these on Alibaba:

1978 and up sealed rear chassis harness side female 6 pin tail light connectors (also used on regulator connectors harness side) (I found the MALE connectors and stock them and the male and female terminals)
1978 sealed park light connectors both harness side (female) and light side (male) uses standard 6.3mm terminals
1972 and up keyed and color coded unsealed fuse block connectors uses standard 6.3mm terminals
1972 to 1977 unsealed Hazard Switch connectors both harness and switch side AND the really weird terminals that fit them
1978 and up sealed dizzy/igniter/emissions/ connectors male and female.

 

[YoYoHo]

@YoYoHo I haven’t started into unwrapping and fixing as needed my ‘63 harness but you’re saying that when I do I’m going to find mechanical splices where splices exist under the original harness wrap and not soldered splices from the factory?

YEP that is exactly what I am saying .

@Coolerman that there is some awesome info and just reinforces why exactly I avoid OEM as I hate the way a lot of things were done back in the day. 99% of what I do now uses Motec PDM and Canbus so it is a very different world to period land cruisers. That being said loom weight has no issues in a cruiser and a lot of what we do is about weigh reduction .

@Coolerman do u have a website with all your connectors listed ?

 

[Coolerman]

Yep, these are not aircraft.... The methods Toyota used back in the day work fine for these old vehicles... 100% reliable? No, easy to fix when they're not? YES!

 

[ToyotaMatt]

some of my KIT

 

[ToyotaMatt]